Week 1 Stock Watch: McCoy, Peterson, Sanchez, Vick

Each Monday, I am going to take a look at some players who have seen a sharp rise or fall in their fantasy value. It may be due to an injury - either their own or a teammate's. It could be because of the emergence of another player on their roster, or an unfavorable match-up. Maybe I just don't like them.

Either way, each week any given player sees his fantasy value fluctuate. Some good. Some bad.

Other players may be somewhere in between, offering hope while at the same time planting a seed of doubt in their owner's mind.

With 14 of the 16 Week 1 games in the book, here is a look around the league at some players who moved the needle this weekend.

Adrian Peterson (RB, MIN) - There were a lot of questions surrounding the health of Adrian Peterson's surgically repaired left knee, but the man they cal "All Day" gave quite a performance in his Week 1 match-up against the Jaguars. The reports before kickoff were that he would be splitting carries with Toby Gerhart, but Peterson got 17 carries to Gerhart's six. Peterson also got in the end zone twice, which likely surprised even those who were daring enough to take him early in their draft. Going forward, there should be no question that Peterson is a must-start running back, as the strength of his knee should only improve. Week 1 Stats: 17 carries, 84 yards, 2 TD

LeSean McCoy (RB, PHI) - If LeSean McCoy proved one thing on Sunday, it was this: He is just as elusive and exciting as he was in 2011. The bad news for McCoy is that he didn't touch the ball nearly enough, and when he did, penalties seemed to negate the yards he gained. Still, Shady finished with 110 yards on 20 carries and added six receptions for another 26 yards. His value couldn't get much higher than it was heading into the season, but fantasy owners probably saw enough troubling signs, from the play calling to the offensive line's struggles. In addition, McCoy failed to reach the end zone, which only happened three times in the 15 games he played last season. Week 1 Stats: 20 carries, 110 rushing yards; 6 receptions, 26 yards

Michael Vick (QB, PHI) - Well that wasn't the start Michael Vick's fantasy owners were hoping for. The Eagles quarterback completed just 29 of his 56 passes and threw four interceptions. Sure, he had a pair of touchdowns and 317 passing yards, but he looked lost at times, and could have easily thrown another interception on the game's final drive (which would have also erased one of his touchdowns). Even more troubling for owners may be the fact that Vick continued to take a beating, showing no signs that he will remain healthy for the entire season. However, if this is how he is going to play, maybe his owners would rather see him on the sidelines. At least that would make for an easier decision on who to start at quarterback each week, especially with match-ups against Ravens, Giants, Steelers, and Lions all before the Eagles hit the bye in Week 7. Week 1 Stats: 29/56 passing, 317 yards, 2 TD, 4 INT; 7 carries, 32 yards

Mark Sanchez (QB, NYJ) - Raise your hand if you saw that one coming. No one? Me neither. Sanchez and the Jets' offense must have been saving all their touchdowns for the regular season. After failing to score a touchdown in the preseason, Sanchez threw for three of them in Sunday's 48-28 blowout of the Bills. Sure, the Bills defense isn't great, but the Jets actually looked like they knew what they were doing. Sanchez has some decent weapons around him, and is making strong case for a spot on your roster. He is only owned in 10.2% of ESPN.com leagues, so if you're in need of a back up - or perhaps a potential starter - you should claim Sanchez before it's too late. Week 1 Stats: 19/27 passing, 266 yards, 3 TD, INT

Trent Richardson (RB, CLE) - Not much good to say about Richardson's performance in Week 1 against the Eagles. The rookie out of Alabama averaged just 2.1 yards per carry, with a long of only nine yards. A slow start is understandable considering he missed the entire preseason after arthroscopic knee surgery, but against a team like the Eagles, who were horrific against the run last season, owners were likely expecting more out of the big back. At least they got this. Week 1 Stats: 19 carries, 39 yards

Martellus Bennett (TE, NYG) - I labeled Bennett as a potential waiver option heading into the season, and the Giants' tight end didn't disappoint, receiving six targets and catching a touchdown in the opener against the Cowboys. With Travis Beckum out, big tight end out of Texas A&M (6-6, 275) should play a significant role in the offense this season. He is only owned in 27.6% of ESPN.com leagues, but that will certainly increase. Be sure to pick him up is you're looking for depth at TE before it's too late. Week 1 Stats: 4 receptions, 40 yards, TD

LeGarrette Blount (RB, TB) - It seems as though it is going to be the Doug Martin show in Tampa Bay this season. That's not good news for Blount owners. Blount netted just 10 total yards in Week one, and with Martin performing well, I don't see any reason that the workload will shift any time soon. If you planned on using Blount as your RB2 or Flex, I would look elsewhere. Don't expect much out of him this season. Week 1 Stats: 3 carries, 8 yards; 1 reception, 2 yards

Matt Forte (RB, CHI) - Forte, like McCoy, had a solid outing in Week 1, but there were some things that could cause owners some worry, specifically Michael Bush. While Forte piled up 120 total yards and a touchdown against the Colts, Bush vultured two goal line scores, something Forte owners have been dreading since their draft. The good news, though, is that Forte looks healthy and didn't show any lingering effects from last season's knee injury. Week 1 Stats: 16 carries, 80 yards, TD; 3 receptions 40 yards

Randall Cobb (WR, GB) - Aaron Rodgers targeted Cobb nine times in their opener against the 49ers and all nine were caught. Packers receivers can be tricky, because Rodgers spreads the ball around. Five different receivers had over 50 receptions in 2011, and seven had over 30, so it is tough to say if Cobb can keep up this type of production. However, it will be hard for Rodgers to stop throwing to Cobb as long as continues to catch everything thrown his way. Cobb gains extra value in leagues where return yards and touchdowns count thanks to his 75-yard punt return TD. Week 1 Stats: 9 receptions, 77 yards, TD

Mike Williams (WR, TB) - Williams' value took a big hit this offseason when the Bucs added Vincent Jackson. Things didn't get much better for Williams in Week 1 as he was only targeted three times. He did make those three catches count, hauling one in for a touchdown. The odds of that happening on a consistent basis are not good, but it would appear that the odds of Jackson getting a majority of the targets going forward are. Week 1 Stats: 2 receptions, 12 yards, TD

Reggie Bush (RB, MIA) - Bush had a solid 2011 season, but many people were down on him heading into this season, mainly because of the return of Daniel Thomas. Well good news for Bush owners: Thomas went down with a neck injury, meaning bush will carry the bulk of the load going forward. Week 1 Stats: 14 carries, 69 yards; 6 receptions, 46 yards.

Matt Mullin is a sports producer at philly.com. You can reach him by e-mail at mmullin@philly.com. Follow Matt on Twitter: @matt_mullin