The big injury of the week is Marion Barber, but how we look at Barber's injury is an interesting point. The Cowboys are already thin at the position, so does losing Barber on top of Felix Jones hurt them more, dropping down to the third-string Tashard Choice?

This isn't the Giants or Jags, who go three deep by plan. I heard more than one analyst this week assessing the injury's affects on the Cowboys, but while one said it was a devastating loss, another would say that against the Steelers solid run defense, it wouldn't matter. I do facts, so I talked with Bill Barnwell, who did some amazing research on the effects of injuries in this year's Pro Football Prospectus.

The fact is that a running back is affected equally by the qualities of a defense. Barber's expected rushing totals might drop more in raw yards, but he's going to be starting with a higher ceiling. Dropping 15 percent off of 100 yards is different than dropping the same percentage from 75 yards. What's interesting is that the RB or lack thereof doesn't seem to have much impact on the passing game. So, yes, the Cowboys will miss Barber if he doesn't play or is limited, but the truth, as it usually is with football, is somewhere in the middle. Let's look at the injuries:

RED

Marion Barber RB DAL: The dislocated toe made it difficult for him to do much aside from running directly into the line. That doesn't work well against the Steelers, so they'll take their chances with Tashard Choice. Barber shouldn't miss much more than this game, but will be watched closely.

Clinton Portis RB WAS: Portis is the very definition of "general soreness." He's probably crossed the soreness threshhold in many cases and with such a broad-spectrum issue, it's hard to say at what stage he loses his edge on Ladell Betts. That's why Jim Zorn makes the big bucks. You don't so unless you have to, move to your backup.

Trent Edwards QB BUF: In what would have been a good matchup for the resurgent Edwards, the groin strain will keep him out and may keep him out longer than the Bills are acknowledging. J.P. Losman's not a bad backup for Buffalo, but there's better on waiver wires for you.

Kellen Winslow TE CLE: We've known he was going to be out and known that Ken Dorsey would be starting. That's two reasons you should have already dumped Winslow.

Desmond Clark TE CHI: Greg Olsen is already getting more targets, but with Clark out, he'll get all of them.

Matt Hasselbeck QB SEA: Things just got worse for the Seahawks. Along with Hasselbeck being unlikely to play, Walter Jones is out. Since Hasselbeck was getting driven into the Texas Stadium turf, leading to this recurrence of his back problems, starting him without Jones would be pure folly. That leaves Seneca Wallace, who is at least mobile enough to run for his life..

YELLOW

Willie Parker RB PIT: It will be interesting to see how a healthy Parker will get apportioned carries. Best guesses are that he'll split them with Mewelde Moore, but even Mike Tomlin is noticing that Moore's been the better back. His knee seems to be holding up, but is still in the recurrence danger zone.

Joseph Addai RB IND: The questionable tag came out of nowhere and has some wondering if it's real, more Colts smoke, or if it's the reason Addai underperformed since returning from his hamstring. He's expected to play, but there could be more Dominic Rhodes than normal in what should be a game for the Colts to run wild.

Matt Schaub QB HOU: Schaub's back from his knee sprain and in practice, showed good lateral mobility. I'm sure they'll test him, but the Texans sources I've talked to over the past couple weeks insist that they wouldn't risk Schaub at all, so he's likely very close to full-go.

Selvin Young RB DEN: Young is finally back, more or less, from his groin strain. That allows everyone the exquisitite torture of figuring out what Mike Shanahan will do with the carries once again. It's the gift that keeps on giving!

GREEN

Brian Westbrook RB PHI: Late word is that Westbrook will start, as expected.

Ben Roethlisberger QB PIT: Remember how everyone panicked a bit midweek when Big Ben twisted his knee? It's a reminder that while you never like seeing the headline, panic doesn't help anyone. He's fine, or as fine as he's been all season.

Steven Jackson RB STL: Last week, Jackson insisted he wasn't tired. Get the sense that Jim Haslett's going to make sure he doesn't say that again this week? Jackson made it through all the practices for the first time and is full-go.

Ryan Grant RB GB: The thumb won't keep him out, but with Brandon Jackson playing well, it could give the Packers reason enough to give Jackson more of the touches. Fumbling is evidently not expected to be an issue.

Reggie Bush RB NO: He's expected to get his normal touches and targets, though having Deuce McAllister back will make the sharing tougher with Pierre Thomas playing well. Bush's knee shouldn't be a problem for the rest of the season. Staying healthy might be.

Roy Williams WR DAL: If Choice can't run, Romo will have to pass. Of course, Williams' foot will need to let him run or he won't get many of those passes. He'll likely play, but need to be spotted in. Expect some three and four wide sets to help him.

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