Fantasy football isn't always fair, especially in crunch time. With a postseason berth on the line, an injury or off game from a stud can keep a team out of the fantasy playoffs.
It's Week 13, so we don't yet have to worry about players being rested for the actual NFL playoffs -- something that will affect your one-loss Falcons and Texans eventually -- but there's a gaggle of players struggling to stay healthy through the 17-week grind.
We focus on those playing at less than full strength in SI.com's last-minute Fantasy Football Cheat Sheet:
1. Two star running backs may return. Don't play them.
Despite how important running backs are in fantasy, not even the most desperate owners should play Oakland's Darren McFadden (ankle) or Dallas' DeMarco Murray (foot) at this point. After surviving weeks without them, praying for big returns this Sunday isn't wise. They'll likely be limited even if they play.
Owners fighting for a playoff berth will surely be tempted to start their long-injured stars, but the risk outweighs the potential reward. If McFadden and Murray have big games on the bench, it'll make it easier to start them next week when the playoffs begin.
2. Avoid these questionable backs as well.
• Beanie Wells (knee), Cardinals: He returned impressively with two touchdowns last week, but he is questionable, playing on the road and is still on an offense clogged up by an awful quarterback situation. Plus, the Jets are better than the numbers indicate and will play well against the inept Cardinals.
• Felix Jones (knee), Cowboys: Jones was hardly useful when he was healthy and the only player in Dallas' backfield. Now he's limited and sharing the load.
• Mike Goodson (ankle), Raiders: Avoid McFadden and his backup Goodson, but consider Marcel Reece (hamstring, quadriceps) a viable starter in deeper fantasy leagues. Goodson isn't worth owning right now, let alone starting.
3. Don't worry about this banged-up Lion.
Some running backs have to be worth starting, right? Yes, and Mikel Leshoure's (ankle) owners can rest easy. The mid-week injury he suffered won't keep him out of a very favorable matchup against a Colts run defense that has been the ninth worst in fantasy against running backs.
Get him active in all leagues, especially in weekly salary-cap formats, where he's a great value.
4. Keep these nicked-up runners active.
• Arian Foster (finger), Texans: Uh, a finger? That's not going to slow the league's best back, who faces a Tennessee defense that is the fourth worst in fantasy versus running backs.
• Matt Forte (ankle), Bears: His sprained ankle steadily improved as the week wore on. He's expected to play against the Seahawks, who boast one of the best run defenses in the league. Keep Forte active, even if Michael Bush will get the goal-line carries. Forte will be a factor in the short passing game, which the Bears will resort to given the strength of the Seahawks' corners.
• Frank Gore (wrist, ribs), 49ers: He might not be 100 percent, but Kendall Hunter (Achilles) is out for the season and there's little chance Brandon Jacobs, Anthony Dixon or rookie LaMichael James are going to take much of a chunk away from Gore in an offense that will still be run-first under Colin Kaepernick. The Rams also happen to be the 11th worst unit in fantasy against running backs.
• BenJarvus Green-Ellis (ankle), Bengals: His ankle injury and the Chargers' fifth-ranked run defense might slow him down amid a hot streak, but BGE has to stay active for fantasy owners. Even if he doesn't crack 100 yards for the third consecutive week, he will likely find the end zone at least once.
• Steven Jackson (foot), Rams: His injury shouldn't concern owners as much as the 49ers' run defense, which is the second best in fantasy versus running backs. Jackson, like BGE, has been rolling lately and rushed for 101 yards and a touchdown at San Francisco just three weeks ago. He's going to get a large chunk of the carries and should prove be to a Top 25 scorer at his position even in this unfavorable matchup.
• Marshawn Lynch (back), Seahawks: He has dealt with a back issue all season, is coming off a terrible performance against the Dolphins and is facing a Bears defense that is the third best in fantasy versus running backs. Lynch has made his name the past two seasons performing well in the toughest of matchups, though. He'll rebound.
Other backs listed on the injury report who are safe to start: Adrian Peterson (shoulder), Trent Richardson (chest, rib, finger), C.J. Spiller (shoulder) and Ahmad Bradshaw (foot).
5. David Wilson gets a Giant opportunity.
Bradshaw has been on the injury report for much of his career, dealing with a chronic foot issue. It's just a matter of how much pain and punishment he can take.
That was where Andre Brown (broken fibula) came in. But with the Giants' TD vulture now out for the season, rookie David Wilson becomes Bradshaw's handcuff.
The 2012 first-round pick is just a few big plays away from making a huge fantasy impact in crunch time and setting up an intriguing 2013. Wilson has shown great speed on kick returns, so seeing him integrated into the Giants' offense is exciting for his owners.
Wilson is available in 55 percent of CBSSports.com leagues and 76 percent of Yahoo.com leagues. If -- really, when -- Bradshaw cannot go, owners who will be happy they stashed Wilson before it was too late.
6. Titus Young's loss is Ryan Broyles' gain.
The Lions didn't take too kindly to Young purposefully lining up in the wrong spots on Thanksgiving Day. Starting in Young's place against the Texans, Broyles was targeted 12 times, reeling in six catches for 126 yards. He will start the rest of the season and this week gets a Colts defense that has been the fifth worst in fantasy against receivers.
With Calvin Johnson drawing a ton of attention amid his four-game streak of 125-plus receiving yards and the Lions remaining wary of drop- and fumble-prone tight end Brandon Pettigrew, Broyles should draw double-digit targets and double-digit fantasy points this week.
He is still available in 53 percent of CBSSports.com leagues and 66 percent of Yahoo leagues. Pick him up and start him in all formats.
7. Expect more headaches from the tight end position.
After last season's record-setting scoring at the tight end position, we've largely been left scrambling for reliable fantasy tight ends on a weekly basis this year. Rob Gronkowski (broken arm) is all but out for the rest of the fantasy season; Jimmy Graham has been marginalized in recent weeks; and early season surprise Heath Miller has to deal with second- and third-string quarterbacks.
That makes Aaron Hernandez all the more valuable this week. We can never know how the Patriots will use their myriad weapons, but they built their offense around Hernandez and Gronk and will want to keep the position involved.
Hernandez is listed as questionable because of the ankle injury that has plagued him for months, but he's ready to come through for fantasy owners in crunch time. The week-to-week inconsistency of the rest of the position makes it easier to gamble on Hernandez this week.
8. Cowboy up? Keep one Dallas receiver down.
Miles Austin (hip) is likely on the right side of questionable even though he's a game-time decision, but don't feel comfortable using him. Austin showed why last week, leaving the game after just two targets and no catches.
The Cowboys have a number of options to use in Austin's place, including Cole Beasley, Dwayne Harris and Kevin Ogletree. If Austin proves healthy and reliable, he'll be an asset in future weeks. But much like McFadden and Murray, he isn't worth the risk in crunch time.
9. The rest of the game-time decisions:
• Wes Welker (ankle), Patriots: He has been playing regularly, despite the Pats' injury-report hijinks. He's active. Keep him active in all leagues.
• Brandon Lloyd (knee), Patriots: He's also active, but he isn't trustworthy given his targets or red-zone looks. With Julian Edelman (concussion) active, avoid Lloyd in most fantasy leagues. Edelman has relegated Lloyd to three-receiver sets.
• Sidney Rice (calf), Seahawks: He's active, but he's not a smart start against Charles "Peanut" Tillman and the Bears' secondary.
• Andre Roberts (ankle), Cardinals: He is out. His replacement Michael Floyd isn't an option either amid Arizona's awful quarterback mess. Plus, the Jets are still a top-10 team in fantasy versus receivers.
• Brandon Stokley (wrist, hip), Broncos: He has been surprisingly involved in the offense and faces the Bucs secondary, which is the second worst in fantasy versus receivers. Mostly, though, that should mean huge days for Demaryius Thomas and Eric Decker.
10. A warning about this week's most-added player:
Owners in nearly 75 percent of CBS leagues added Denver's Knowshon Moreno this week. Here's the rub: There's a timeshare in Denver, and both of those backs will be facing Tampa Bay's No. 1 run defense Sunday.
Moreno's owners thought they were acquiring a surprise feature back, but that's probably not going to be the case. Rookie Ronnie Hillman is going to get a bigger chunk of the carries and Lance Ball still might be the back of choice at the goal line.
Don't start Moreno, Hillman or Ball this week.
A few remaining last-minute notes posted on Twitter @EricMackFantasy:
• No Jonathan Stewart today means a decent week to expect DeAngelo Williams to total 60 yards and get a TD.
• No Visanthe Shiancoe for the Pats. Expect Aaron Hernandez to be a frequent target today.
• Greg Jennings is active, but figure he will be limited to 4 catches for 50 yards and no TDs in his first game back. James Jones takes a hit.
• Percy Harvin is inactive. Jarius Wright is slightly more intriguing today, especially with the expectation of garbage time against Packers
• Titus Young inactive. Love Ryan Broyles against the Colts here.
• Donald Jones is inactive. Stevie Johnson and Scott Chandler are going to get slightly more targets, but this game is about the RBs
• Danny Amendola is inactive.... Chris Givens is only slightly more intriguing.
Eric Mack writes fantasy for SI.com. Track his weekly starts and sits every Thursday, his last-minute Cheat Sheet on Sunday mornings 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).