Each week of the NFL season, a committee of SI.com fantasy experts will huddle together and offer their insights into the most intriguing questions facing fantasy players.

1. Another week and more expected star running backs are struggling. Whose future are you more concerned about the rest of this season: Rashard Mendenhall or Peyton Hillis?

Will Carroll: Mendenhall -- the Steelers line is really struggling and we saw that the team has productive alternatives in Mewelde Moore and Isaac Redman. With Redman already in position to steal red zone touches, Mendenhall is going to have all sorts of issues around him and perhaps no Ben Roethlisberger in front of him.

Gary Gramling: Mendenhall. The Steelers have had offensive line issues for years, but this is as bad as they've ever been. They can't block, Mendenhall's nursing a groin injury, his role in the passing game hasn't been expanded (as promised) and, oh yeah, Isaac Redman is performing just as well if not better than Mendenhall to this point. Strep throat really knocked Hillis on his ass, but he's looked fine when healthy and should be fine going forward. He isn't going to be taking 95 percent of Cleveland's reps every week like he did a year ago, but we knew that coming into the season. And we also know that Montario Hardesty hasn't done anything to close the gap between them. If I were drafting today, I'd take Hillis right around 10.

Eric Mack: The immediate future of Mendenhall is more worrisome because of his health and the health of the key cog in the Steelers offense, Roethlisberger. Without either, the Steelers will struggle all around. Mendenhall and Big Ben both need to be healthy. Peyton Hillis is more of a long-term future worry -- if you even drafted him. He just isn't that good and was a function of a surprise year that he won't ever duplicate. You should have avoided him on draft day. Mendenhall has a much higher ceiling.

David Sabino: I'm much more concerned with Mendenhall. In part that is because of his pulled hamstring, which could nag him for a while, but more because his problems seem to be directly related to the Steelers injury-decimated offensive line. It doesn't matter how good a back is, if he doesn't get the necessary holes, he just can't gain a lot of yards. Hillis is a bulldozer and has the added bonus of having good receiving skills. The Browns O-line is one of the better ones in the business and Hardesty is no threat to take over a majority of Cleveland's carries just yet. Go with Hillis.

2. Ryan Torain grabbed the bulk of the carries and yards for the Redskins in Week 4. Is he now the man in Washington or can owners still trust in Tim Hightower?

Carroll: None of the above? Have we all forgotten that Mike Shanahan hates fantasy players? He'll mix and match RBs all day, starting one you didn't expect and then giving carries to another. Helu has been pretty nice, too, so you've got a situation where you not only have to predict what a player is going to do, but what a coach is going to do. No thanks.

Gramling: There is no main man in this backfield. Both Torain and Hightower are worth owning, but you'll have to read the Shanahan tea leaves week-to-week. He hinted at a bigger role for Torain leading up to Sunday; it just seemed unfathomable that a guy with zero touches on the year would leapfrog two backs who had turned in decent performances to that point. At this point I wouldn't be surprised to see Gerald Riggs log a dozen carries in Week 5. The Washington backfield situation has officially become toxic.

Mack: No. Shanahan created the modern-day running back rotations with what he did back in the late Terrell Davis days. Now, Hightower is in the doghouse and the Redskins are likely to ride the hot hand. You are going to be stuck playing running back roulette with Hightower and Torain for the foreseeable future -- and, who knows, Roy Helu just might wind up stealing time, too.

Sabino: Until Mike Shanahan finds his new Terrell Davis in D.C., I don't think you can depend on any of the Skins backs, including rookie Roy Helu. However, if you have to play someone, I would go with Torain against weaker opponents and Hightower against stronger defenses.

3. After the season's first quarter, what one player would you sell high on?

Carroll: Ryan Fitzpatrick. He's a nice story -- did you know he went to Harvard? -- and so are the Bills, but there's a lot more depth at the QB position than people recognize. If you have Fitzpatrick on your team, you probably drafted him as a QB2. If you have a decent option at QB1 -- even if it's someone with a bit less production right now than Fitzpatrick, like, say, Philip Rivers or Matt Ryan -- then it's a smart play to use Fitzpatrick to upgrade somewhere else.

Gramling: Darren McFadden. I still don't think he stays healthy as a 20-touch guy, and some of the more unique aspects that are making the Raiders running game go will become less effective the more the rest of the NFL sees them. A lot of people consider him the best player in fantasy football right now, so you could get a monster return. (There are also the obvious guys like Ryan Fitzpatrick, Matt Hasselbeck, etc., but there really shouldn't be much of a market for them).

Mack: It hurts to say this, because he has been such a pleasant breakthrough to watch, but Jimmy Graham is one of the most valuable bargaining chips right now. Graham is performing like the No. 1 tight end in fantasy, and we all should remember tight ends just aren't as important as elite receivers, running backs or quarterbacks. If you have Graham and a hole at one of those other spots, sell high on him to get potential at those more impactful positions and back-fill your tight end spot with a new player every week, say a Brandon Pettigrew, Jared Cook, Benjamin Watson or an Aaron Hernandez coming off an injury.

Sabino: I was going to say Cam Newton but I'm through underestimating what the kid can do. With no cold weather games on the schedule, he may be able to keep up a pace that has made him the third-best fantasy quarterback. Given that, I don't think that Matt Forte can keep up the incredible yardage pace he's been on. It's becoming obvious that he's the only Bears offensive player that defenses need to concentrate on, and they will.

4. Who stands to gain the most if the struggling Vikings make a change at quarterback?

Carroll: Opposing defenses? The Vikings have one real weapon right now (Adrian Peterson) and one potential one (Percy Harvin.) Neither is helped by switching to rookie Christian Ponder. I like Ponder long term, but this is a bad situation, and the Vikings would be better served sticking with McNabb for now. Check again in four weeks.

Gramling: Besides Joe Webb/Christian Ponder, who becomes a QB3 in deep leagues, probably no one. Maybe Harvin will be utilized more because of his catch-and-run ability. Kyle Rudolph becomes a somewhat intriguing TE2 if Ponder gets the call, since that would indicate a youth movement. But Peterson would continue to be the only startable player on this team. He'd continue to see all the eight-man fronts he sees with McNabb under center, and the Vikings will have all the same issues scoring points they had with McNabb under center.

Mack: Peterson. Donovan McNabb is catching undue flak in the Twin Cities. Brett Favre did, too. The receivers in Minnesota just aren't NFL caliber. McNabb is going to make something out of Percy Harvin once the Vikings actually start unleashing Harvin in the passing game (they tend to want to use him in the running game more). If the Vikings punt on the season and go to Ponder, there will be a lot more weight shifted on to the capable shoulders of Peterson. Frankly, all the Vikings are going to be worse off with a rookie passer over McNabb -- in this writer's estimation.

Sabino: The player most likely to feel the effects will be Peterson, but in a negative way. McNabb has not been good but commands the respect of opposing defenses because they know if they cheat too much to stop AD, then McNabb can, and has, beaten them. But with Ponder in at QB, not only will they stack the line with seven- and eight-man fronts to stop Peterson, they're going to bring the kitchen sink on passing plays to pressure the youngster. That should boost the value of Harvin, who is one of the league's most dangerous yards after the catch guys, especially on screen plays.

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