Updates on Adrian Peterson, Marshawn ...

Well, the first game of the 2012 NFL regular season is behind us. Given the altered schedule this week, today we'll look at some key players whose status could be in flux in advance of Sunday's games. There are many more players to discuss, and Saturday will mark the return of the sizable pregame injury blog. Saturday's entry will include injury breakdown by position and official designations on the teams' final injury reports.

In the meantime, here are a few players to keep an eye on:

• Vikings running back Adrian Peterson (knee) has made his readiness and his eagerness to return well-known, and on Thursday, Vikings offensive coordinator Bill Musgrave told reporters he has "not too much doubt" that Peterson will play. According to Dan Wiederer of the Minneapolis Star-Tribune, the Vikings will determine Peterson's playing status either Friday night or Saturday morning.

Musgrave also indicated to ESPN 1500 Twin Cities that there are a limited number of plays in mind for Peterson. We have maintained all along that the Vikings would likely ease him back into a regular workload, and it appears they plan to do just that. Peterson could be limited to just a few series.

• Seahawks running back Marshawn Lynch is no lock to play this weekend after being sidelined for the past two weeks because of back spasms. With regard to Lynch's status, Seattle coach Pete Carroll told reporters Thursday he "really won't know until the end of the week unless something changes." This is not Lynch's first episode of back spasms, either. He has dealt with something similar on an occasional basis over the past four years; the challenge is not knowing when a flare-up will occur or how long it will last. The Seahawks are making preparations in the event that Lynch cannot play Sunday against Arizona (translation: Robert Turbin would start), but this may come down to a game-time decision.

• Browns first-round pick Trent Richardson is likely to take the field Sunday, although it's unclear how much playing time he will see. Richardson, recovering from his second knee surgery this year, told the Cleveland Plain-Dealer that "... in my mind, I'm ready. I can't wait to see what the results are going to be on Sunday." The Browns have been cautious with their rookie running back in his return to practice and are likely to limit his touches Sunday as well.

New Orleans Saints wide receiver Marques Colston was out of practice Wednesday because of a sore foot. He returned to limited practice Thursday and appears to be on track to play Sunday.

• Panthers running back Jonathan Stewart has yet to practice since injuring his ankle during the preseason, but don't write him out of the Week 1 game plan just yet. Earlier this week, coach Ron Rivera said he was "encouraged" by Stewart's progress, and indicated the veteran back would travel with the team to Tampa. It's worth noting that despite dealing with foot and ankle issues in the past, Stewart has played in all 16 games three out of the four seasons he has been in the NFL.

• Bills wide receiver Stevie Johnson is still having intermittent soreness in the groin area following offseason surgery. It is not uncommon for athletes to experience this, particularly as they ramp up activity. On several occasions during training camp, the team opted to rest Johnson when the soreness cropped up, and the Bills did so again Wednesday, restricting him to "limited" practice. Johnson recently described himself as "90-something percent" recovered according to the Bills' official website, adding, "I only say 90 because no one is really 100 percent unless you haven't been playing at all, but I'm good." Last year Johnson played -- and was productive -- while injured, so it doesn't appear as of now that this is a big threat to his status.

See you at my injury chat Friday at 11 a.m. ET, and I'll have the latest Week 1 injury updates in my Saturday morning blog.