This is a week of the irresistible forces vs. the immovable objects. The top two offenses (New England and the N.Y. Giants) face the top two defenses (Seattle and San Francisco).
The Giants offense has been romping for fantasy owners, even with spare parts at times, and next faces arguably the best defense in the NFL, even if the up-tempo Tom Brady spread offense is facing the defense that is statistically No. 1. The former portends Week 5 surprise star Ahmad Bradshaw may prove to be Week 6's bust against the toughest run defense in the NFL.
Fantasy's other toughest opponents vs. running backs are threatening to cut into the production of some of the steadiest running backs: Alfred Morris (vs. MIN), Stevan Ridley (at SEA), LeSean McCoy (vs. DET), Fred Jackson and C.J. Spiller (at ARI), Steven Jackson (at MIA), Marshawn Lynch (vs. NE), Adrian Peterson (vs. WAS) and Jamaal Charles (at TB).
The good news, perhaps, is you can at least still start those guys even in unfavorable matchups. Then, of course, there's Chris Johnson, the mercurial fantasy pariah stuck on a Tennessee roller-coaster ride, who should sit vs. the Steelers' run defense, which is still rugged.
The question marks don't end there. Some more of the marquee names are on bye as Carolina, Chicago, Jacksonville and New Orleans get the week off. The likes of Drew Brees, Cam Newton, Maurice Jones-Drew, Jimmy Graham, Marques Colston, Brandon Marshall, Matt Forte, Garrett Hartley, Robbie Gould and the Bears defense/special teams are unavailable to you.
We'll help you plug those gaps and others in SI.com's weekly Start 'em, Sit 'em:
• Steelers -- Ben Roethlisberger, Rashard Mendenhall, Mike Wallace, Antonio Brown, Heath Miller, Shaun Suisham, Steelers D/ST: This is a dream matchup to start all of your primary Steelers. The Titans are favorable across the board in fantasy: vs. quarterbacks (sixth), running backs (seventh), wide receivers (16th), tight ends (first), kickers (second) and D/STs (sixth). Mendenhall was solid in his return against a much tougher defense, so consider him a potential top-five running back going forward. Miller was hot going into the bye and gets a great matchup here. Even Isaac Redman might be a flex option, as this game may become a blowout and allow some grind-it-out garbage time.
• Titans -- Jared Cook: The Steelers are a tough defense, but also a tough team that figures to get ahead and lead to some garbage time. Cook picked up five catches for 37 yards and a touchdown in the fourth quarter last week, so expect him to be a frequent target again. If you need a receiver, Kenny Britt is healthy, Kendall Wright was frequently targeted last week and Nate Washington was huge with Matt Hasselbeck a year ago. None of the three are great options, but they are potentially useful as stopgaps.
• Steelers -- Jonathan Dwyer, Emmanuel Sanders, Jerricho Cotchery: Sanders and Cotchery might find the end zone as the Steelers spread the ball around, so consider them decent desperation options if injury and bye weeks really have you scrapping for dregs.
• Titans -- Matt Hasselbeck, Chris Johnson, Rob Bironas, Titans D/ST: Johnson is probably the only one of these owned, but he is the one that should be sat. His surprise performance against the Texans' run defense shouldn't be used as a guide to start him against the Steelers, who can still beat up backs. This is a short week, which always can affect backs and their amount of usage, and you likely are already well-equipped to do without Johnson in your lineups.
• Raiders -- Darren McFadden, Sebastian Janikowski: The Falcons have a better run defense than their current standing as the 12th-worst in fantasy vs. running backs, but McFadden should prove productive in this matchup, if not on the ground, then through the air. This looks like a week of a lot of garbage time for the Raiders as the Falcons tend to score at will, so consider Carson Palmer and his primary target Denarius Moore potential sleepers. Janikowski has been limited with a groin issue, but the bye week should have healed that. Consider him someone to pick back up and set-and-forget in lineups the rest of the way.
• Falcons -- Matt Ryan, Michael Turner, Julio Jones, Roddy White, Tony Gonzalez, Matt Bryant: There are good signs for all of the star Falcons here, especially Turner, who faces a Raiders defense that has been bottom-five against running backs in fantasy to date. That fact might even make seldom-used backup Jacquizz Rodgers a potential flex in deeper formats, if he mops up.
• Raiders -- Darrius Heyward-Bey, Rod Streater, Derek Hagan, Brandon Myers: Palmer's secondary targets are not necessarily worth owning yet, save for DHB, who is coming off a concussion. DHB is practicing now, but he needs to prove healthy and productive before he is to be trusted in fantasy lineups.
• Falcons -- Falcons D/ST: Many are going to jump on this unit against a sub-standard Raiders team, but it might come as a surprise the Raiders have averaged the fewest fantasy points against because they have committed just three turnovers and allowed just five sacks. Only the Texans are stingier with turnovers through four games.
• Cowboys -- DeMarco Murray, Miles Austin, Dez Bryant, Jason Witten: The Cowboys have been a mess, but this group looks pretty safe to start coming out of the bye. Murray is especially interesting against a Ravens run defense that has somewhat surprisingly been in the bottom half of fantasy against running backs.
• Ravens -- Ray Rice, Justin Tucker, Ravens D/ST: It might be lost in their 1-3 start, but the Cowboys are a tough matchup in fantasy against the pass. They are No. 2 and No. 3 vs. quarterbacks and receivers. You shouldn't ever sit Rice, Tucker or the Ravens D/ST, though.
• Cowboys -- Tony Romo, Kevin Ogletree, Dan Bailey, Cowboys D/ST: These guys have really slipped, and since fantasy owners managed without them a week ago, the advice here is leave them out of lineups for at least one more week.
• Ravens -- Joe Flacco, Torrey Smith, Anquan Boldin, Dennis Pitta, Ed Dickson: Flacco, Smith and Boldin are useful as needed, but owners might be better off with other options against a Cowboys defense that can slow the passing game with their pressing corners.
• Bengals -- BenJarvus Green-Ellis, A.J. Green, Jermaine Gresham, Mike Nugent, Bengals D/ST: BGE is coming off a disastrous outing, but Bernard Scott (knee) is now out for the year and the Browns allowed the Giants to run wild on the ground a week ago. It should be a better week for BGE, while Gresham should be able to continue his recent resurgence. Nugent is a nice option at kicker in most weeks, while the Browns are in the bottom half of fantasy against opposing D/STs.
• Browns -- Trent Richardson: The Bengals have been the eighth-most forgiving team in fantasy vs. running backs, so Richardson should be able to continue his rushing-touchdown string, while being a big factor in the passing game as well.
• Bengals -- Andy Dalton, Armon Binns, Andrew Hawkins: The Browns are getting their elite cornerback Joe Haden back, so expect the defense to be much tougher all around against the pass this week. That makes Dalton and his secondary targets question marks this week.
• Browns -- Brandon Weeden, Greg Little, Josh Gordon, Mohamed Massaquoi, Travis Benjamin, Jordan Norwood, Ben Watson, Phil Dawson, Browns D/ST: Save for Richardson, the rest of the Browns' fantasy options aren't worth owning right now, especially against a defense that should improve upon its slow start.
• Rams -- Steven Jackson: This poor running back has run a gauntlet of elite run defenses this season. This week quietly presents one of the toughest. The saving grace here, though, is that Jackson is the best thing the Rams offense has going for it. He will get his touches and yards even against a Dolphins defense that is No. 1 in the NFL against the run.
• Dolphins -- Reggie Bush, Dolphins D/ST: Bush remains a solid option in all leagues, even if he loses goal-line touches to Daniel Thomas and isn't quite 100 percent. The Dolphins defense has been surprising, especially at home, and faces a Rams team that has been the eighth-worst in fantasy against D/STs.
• Rams -- Sam Bradford, Brandon Gibson, Chris Givens, Steve Smith, Brian Quick, Austin Pettis, Lance Kendricks, Greg Zuerlein, Rams D/ST: The loss of Danny Amedola for the season makes a further mess of a bad situation with the Rams. One of these receivers need to step forward, but until one does, you should avoid all of these options in fantasy.
• Dolphins -- Ryan Tannehill, Daniel Thomas, Brian Hartline, Davone Bess, Anthony Fasano, Dan Carpenter: Tannehill and the Dolphins have shown flashes, but they are facing a Rams team that has been equally surprising in the early season. Thomas might find the end zone and Hartline might find some targets, but you're better off looking elsewhere for stopgaps this week.
• Colts -- Andrew Luck, Reggie Wayne, Adam Vinatieri: Luck has earned starting status by handling a top contender in the Packers at home. He has been great, mostly because Wayne has never looked better, despite his advanced age. Vinatieri is coming back to prominence in fantasy, too, because Luck has been so capable.
• Jets -- Shonn Greene: Greene and the Jets have been an unmitigated disaster, but the run defenses of the Steelers, Dolphins, 49ers and Texans will do that to the best the NFL. This week Greene could rebound gloriously for fantasy owners against a Colts defense that is ninth-worst in fantasy vs. running backs. Greene is headed for 125 yards and two scores. You heard it here first.
• Colts -- Vick Ballard, Delone Carter, Donald Brown, Donnie Avery, T.Y. Hilton, LaVon Brazill, Coby Fleener, Dwayne Allen, Colts D/ST: Ballard takes over as a starter with Brown needing a knee 'scope this week, but the Jets defense is better than it has shown against some of the elite running games in the NFL. Rest assured, this is not a good Colts running game it will be facing. The receivers are a risk, too, against a secondary that kept the Texans reeling a bit.
• Jets -- Mark Sanchez, Stephen Hill, Jeremy Kerley, Chaz Schilens, Dustin Keller, Nick Folk, Jets D/ST: All of these guys have been worthless of late, so don't use them as much as track them. Someone is going to take advantage of a favorable matchup here. The bet is Sanchez, Keller, Folk and the defense surprise, so consider them out of desperation if byes and injuries have you scraping the bottom of the barrel.
• Lions -- Matthew Stafford, Mikel Leshoure, Calvin Johnson, Brandon Pettigrew, Jason Hansen: This doesn't register as a great time to expect a rebound from your struggling Lions -- the Eagles are among the best vs. quarterbacks (fifth), running backs (11th), receivers (15th) and tight ends (fifth) -- but these options rate as solid starts against almost any opponents.
• Eagles -- Michael Vick, LeSean McCoy, DeSean Jackson, Jeremy Maclin, Brent Celek, Alex Henery, Eagles D/ST: The Lions, like the Eagles, are not necessarily a defense to try to exploit in fantasy, especially against the run (fifth-best in fantasy vs. running backs). These options should all be immune to the matchups during the bye season, though. Celek might be a question mark, but he has the best matchup of the group. The Lions have averaged the fourth-most points allowed to tight ends to date. Maclin proved healthy last week, so get him back in lineups, too.
• Lions -- Joique Bell, Titus Young, Nate Burleson, Tony Scheffler, Lions D/ST: The Eagles might not be an opponent to rest studs against, but they are good enough to ignore these stopgaps this week.
• Eagles -- Bryce Brown, Jason Avant, Darnaris Johnson, Clay Harbor: Save for Brown as a McCoy handcuff, these guys should stay off fantasy rosters, much less out of lineups.
• Chiefs -- Jamaal Charles, Dwayne Bowe: This isn't a great week for must-start Chiefs, but Charles and Bowe have proved worthy against good defenses. Keep them active, even if Matt Cassel (concussion) cannot play. The Bucs are third-worst in fantasy vs. wide receivers.
• Buccaneers -- Doug Martin, Vincent Jackson, Buccaneers D/ST: Martin has slipped after a hot start, but he should rebound here against the Chiefs, who are in the bottom 10 of fantasy vs. running backs. Jackson also has must-start status, despite the Chiefs secondary ranking in the top 10 against receivers. Josh Freeman and Mike Williams aren't great options in this matchup, but they are at least serviceable ones if you're in need of stopgaps due to byes or injuries. The Bucs defense has been surprisingly good, especially at home, so consider them a streaming option if you need a sleeper D/ST this week.
• Chiefs -- Brady Quinn, Peyton Hillis, Shaun Draughn, Jon Baldwin, Steve Breaston, Tony Moeaki, Ryan Succop, Chiefs D/ST: Hillis (ankle) likely won't play and the rest of these guys are big question marks with Quinn expected to be under center with Cassel out.
• Buccaneers -- LeGarrette Blount, Dallas Clark, Connor Barth: The Bucs say they want to get the ball to Blount more, but until they do, he's not a reliable fantasy option. Clark and Barth might be later on during the bye season, but don't trust them right now.
• Bills -- Fred Jackson, C.J. Spiller, Stevie Johnson: The Cardinals are the sixth-best team in fantasy vs. running backs, but Jackson and Spiller owners should let out a huge breath now that the 49ers run defense is in the rear view on the schedule. Jackson and Spiller will be more productive, if only because the Bills re-affirm the best chance they have to move the ball. Johnson is a go against a Cardinals defense that is in the bottom half of fantasy vs. WRs to date.
• Cardinals -- Larry Fitzgerald, Andre Roberts, Cardinals D/ST: This is easily the Cardinals' best matchup of the year, but this trio represents the lone trustworthy options. Kevin Kolb is too up-and-down to completely trust, despite the Bills being the worst team in fantasy vs. quarterbacks, and the running back situation is still unclear, despite the Bills being the second-worst team in fantasy vs. running backs. William Powell might start, but if La'Rod Stephens-Howling plays, he might outscore Powell. Use Kolb and those two backs as needed. Lastly, the Bills are fourth-worst in fantasy vs. receivers, so the surprising Roberts is good start in deeper formats, especially three-receiver leagues.
• Bills -- Ryan Fitzpatrick, Tashard Choice, Donald Jones, T.J. Graham, Scott Chandler, Rian Lindell, Bills D/ST: Last week should have taught you the Bills are going to be frustrating options on the road against a good defense. The Cardinals qualify. Jones is someone to watch if this game gets loose, but it is more likely the Cardinals play down to their competition here.
• Cardinals -- Alfonso Smith, Michael Floyd, Early Doucet, Jay Feely: Floyd is the only one worth owning in fantasy and he's far too inconsistent in an inconsistent offense to dare starting him right now.
• Patriots -- Tom Brady, Stevan Ridley, Wes Welker, Rob Gronkowski, Stephen Gostkowski, Patriots D/ST: The Seahawks currently have the No. 1 defense in the NFL, performing No. 1 vs. quarterbacks, No. 4 vs. running backs, No. 6 vs. receivers and No. 4 vs. tight ends in fantasy. Seattle's victory over Green Bay at home was impressive, even if not referee-aided, but the Pats own the best offense in the NFL right now and takes the no-huddle to a whole new level. Keep the top-tier Pats fantasy stars active, including the defense, which gets to pin its ears back against a shaky rookie quarterback.
• Seahawks -- Marshawn Lynch: The Pats defense is suspect in some respects, especially vs. quarterbacks (second worst), but it actually is in the top 10 vs. running backs in fantasy. Still, Lynch cannot be benched; he is too important to his team's offense and his fantasy owners. Russell Wilson should be able to post some numbers, despite his struggles, but don't use him, Sidney Rice or Golden Tate unless you're desperate.
• Patriots -- Brandon Bolden, Danny Woodhead, Shane Vereen, Brandon Lloyd, Aaron Hernandez: The backup running backs aren't a great play against a very good Seahawks run defense, while Hernandez is a question mark due to his ankle and Lloyd is facing a very good secondary. These guys should be owned, but this might be one of their most unfavorable matchups of the year. Seattle's 12th man is tough at home. Ask the Packers.
• Seahawks -- Doug Baldwin, Zach Miller, Steven Hauschka, Seahawks D/ST: The Seahawks defense will have better weeks than this one. They held up against the Packers, but the Pats present far more diverse challenges. Miller has the best matchup of this lot -- the Pats are second-worst against tight ends -- but Wilson just isn't functional enough as a downfield passer to trust any of these secondary Seahawks.
• Giants -- Eli Manning, Victor Cruz: This is the only week of the year to be pessimistic about the Giants offense. It wasn't good in Philly and it could be worse in San Francisco, especially if Hakeem Nicks (foot, hip) does not play. Nicks is a risk, even if he does. Despite facing the defense that is No. 6 in fantasy vs. quarterbacks, Manning should be good for 250 yards and a score or two, so keep him active if you don't mind those numbers from the quarterback position this week. Cruz figures to be heavily targeted in the short routes and maybe a shot or two deep, if the Giants can get some protection for Manning.
• 49ers -- Alex Smith, Frank Gore, Michael Crabtree, Vernon Davis, David Akers, 49ers D/ST: The Giants' defense shouldn't scare anyone off the red-hot 49ers. Even Mario Manningham, facing his former team, is a decent option against a banged-up secondary that is seventh-worst in fantasy vs. receivers. Most of these guys are must-starts at home, regardless of the matchup. Smith is a nice stopgap at the quarterback position, coming off his 300-yard, three-score week.
• Giants -- Ahmad Bradshaw, David Wilson, Andre Brown, Domenik Hixon, Ramses Barden, Rueben Randle, Martellus Bennett, Bear Pascoe, Lawrence Tynes, Giants D/ST: These guys can be fantasy stars in some weeks, but against the 49ers they shouldn't be touched. Bradshaw is the toughest sit, coming off his 200-yard performance. The 49ers are No. 1 in fantasy vs. running backs and No. 1 vs. receivers, too.
• 49ers -- Kendall Hunter, Brandon Jacobs, Anthony Dixon, Randy Moss, Kyle Williams: These guys can be factors in some blowout weeks like the past couple, but this doesn't figure to be one. The Giants are going to keep it close and they guys should have a minimal impact on the game.
• Vikings -- Christian Ponder, Adrian Peterson, Percy Harvin, Kyle Rudolph, Blair Walsh, Vikings D/ST: The Redskins are third-worst in fantasy vs. quarterbacks and tight ends and the worst against receivers. This should be a good week for the Vikings offense, including their hot rookie kicker. The defense is more of a risk in a game that should be a shootout, but they have proved solid against the likes of the 49ers and Stafford's Lions. They remain one of the top 12 units to start this week.
• Redskins -- Robert Griffin III, Alfred Morris, Pierre Garcon, Fred Davis: These starts are all contingent on RGIII's health. We should expect him to play, so Garcon and Davis start as well, while Morris has earned must-start status. If Kirk Cousins starts, we might only like Morris.
• Vikings -- Toby Gerhart, Jerome Simpson, Michael Jenkins: The Vikings are expecting Simpson to play with a back issue, but he was blanked against the Titans and is difficult to trust, along with these other also-rans.
• Redskins -- Evan Royster, Ryan Grant, Santana Moss, Leonard Hankerson, Josh Morgan, Aldrick Robinson, Kai Forbath: These guys might eventually be fantasy worthy in spurts this season, but they aren't worth owning right now.
• Packers -- Aaron Rodgers, Jordy Nelson, James Jones, Mason Crosby: This is one of the few weeks to be wary of the Packers. The loss at Seattle wasn't that poor of a fantasy day for them, but this one might be worse, especially with the question marks around health at running back, receiver and tight end.
• Texans -- Arian Foster, Andre Johnson, Owen Daniels, Shayne Graham, Texans D/ST: Johnson is the only real question mark, coming off his quiet Monday night performance, but the Packers are 11th-worst in fantasy against receivers to date.
• Packers -- Alex Green, James Starks, Greg Jennings, Randall Cobb, Jermichael Finley, Packers D/ST: Green should start with Cedric Benson on the designated-for-return IR, but he will be facing a Texans defense that is in the top-10 in fantasy vs. running backs. Jennings (groin) is a risk if he plays, while Cobb is a sleeper but the Texans defense is tough and the targets just haven't been consistent. Finley is dealing with injury, too, and the Texans are the seventh-stingiest team vs. D/STs.
• Texans -- Matt Schaub, Ben Tate, Justin Forsett, Kevin Walter, Keshawn Martin: Schaub had a frustrating performance against the Jets last Monday, so the safest course of action is to bench him, even if the Packers are in the bottom 10 of fantasy vs. quarterbacks. The Texans' backups are intriguing in more favorable matchups, but should be avoided here.
• Broncos -- Peyton Manning, Willis McGahee, Demaryius Thomas, Eric Decker, Matt Prater: You shouldn't need a compelling argument to start Manning any longer, but the Chargers are 10th-worst in fantasy vs. quarterbacks. It should make for a productive week for the entire Broncos offense, including Jacob Tamme and maybe even Brandon Stokley if you need sleepers as stopgaps.
• Chargers -- Philip Rivers, Ryan Mathews, Malcom Floyd, Antonio Gates, Nick Novak: While the Broncos defense is better than it has shown in a brutally tough early-season schedule, there isn't anything that should keep you from starting these primary Chargers. Gates, who has been a huge disappointment, should be given a go against a Broncos defense that has been ninth-worst in fantasy against tight ends. Even Robert Meachem might be viable. Start Novak at kicker, too, in Nate Kaeding's (leg) absence.
• Broncos -- Ronnie Hillman, Lance Ball, Knowshon Moreno, Joel Dreessen, Broncos D/ST: This should be a shootout, but none of these options are consistent enough to own in fantasy, much less start right now.
• Chargers -- Jackie Battle, Eddie Royal, Chargers D/ST: Battle might still get carries and goal-line touches, but the Broncos' run defense is a lot better than the middle of the pack unit it has performed like to date. Royal can be a sleeper in deeper leagues, but he and the Chargers defense just aren't high enough in this week's rankings to warrant a look.
For those of you that play in salary-cap games, here is the lineup we would advise:
QB -- Matt RyanRB -- Shonn GreeneRB -- Frank GoreWR -- Larry FitzgeraldWR -- Demaryius ThomasTE -- Antonio GatesFLEX -- Michael TurnerK -- Mike NugentD/ST -- Tampa Bay Buccaneers
Think you have a better lineup? Challenge me with it on Twitter @EricMackFantasy.
Eric Mack writes fantasy for SI.com. Track his weekly starts and sits every Thursday, his Scouting Report on Friday and his Fantasy Fast Forward on Sunday nights. You find also him on Twitter, where you can mock him, rip him and (doubtful) praise him before asking him for fantasy advice or challenging him to a head-to-head fantasy game @EricMackFantasy. He reads all the messages there (guaranteed) and takes them very, very personally (not really).