Da'Quan Bowers, DE, Clemson
Bowers played half of his 2010 season — and picked up about half his sacks — on a torn meniscus that was scoped out after the season. He passed on the combine and pushed back his pro day to get back in shape through the rehab process, and probably wasn't ready to run when he did so for NFL scouts, coaches and personnel people. Those watching will forgive a bad pro day based on Bowers' game tape (which is fairly ridiculous), but the specter of the long-term knee problem could have him drop from a possible top-3 prospect in-season to the mid- or late-first round. Bowers has cleared every medical test he's taken, and it's crucial to point that out, but one never knows how gun-shy teams will be.
Jake Locker, QB, Washington
One of the most interesting memes of the 2011 pre-draft process is the notion that had he come out as a junior for the 2010 draft, Locker would have been a top pick; perhaps even rivaling Sam Bradford for the No. 1 spot. Locker is an amazing athlete, a great kid, and he's got loads of potential, but as much as he brings to the position, the accuracy and mechanical issues that plagued him as a senior were just as present in years before. The drop is therefore a bit of a misnomer, but Locker may have pushed himself back into the top 10 with some impressive postseason workouts.
Adrian Clayborn, DE, Iowa
After a 2009 season in which he put up 11.5 sacks and dominated his opponents, Clayborn fell back to earth in 2010 with just 3.5 quarterback takedowns and a tendency to look more mortal on tape. Adding in the fact that he was born with a condition called Erb's Palsy, which could affect his right shoulder and arm and make him a better player on one side, means that Clayborn could very well fall from a top-10 prospect to the late first round.
Nick Fairley, DT, Auburn
The good news for Nick Fairley is that he reminds people of Albert Haynesworth. The bad news? Pretty much the same thing. While he brings nonpareil disruptive ability from the tackle position in his draft class, Fairley also leaves questions about his motor, work ethic, maturity and ability to play clean. He's drawn many flags for playing after the whistle, and that's not something the NFL fools around with these days. Fairley may go as early as the eighth pick to Tennessee, where former Auburn coach Tracy Rocker is now on staff and will no doubt be pounding the table for the man he used to mentor, but teams may be wary of putting tens of millions of dollars on the Fairley marker, given the risk/reward equation.
Christian Ponder, QB, Florida State
At one time, Ponder was thought to be a lead-pipe lock for the top 10. Then, two shoulder surgeries and an elbow procedure got people thinking that he might not even make it to the NFL. Ponder recovered in time to put up an MVP performance at the Senior Bowl and looked great at the combine, but his injury history got people looking at his lack of a deep ball in general and overlooking his command of a pro-style offense and ability during Senior Bowl practices to zip the ball downfield. The most instantly pro-ready quarterback in this class, Ponder will likely go late in the first round or early in the second.
Ras-I Dowling, CB, Virginia
Dowling was believed to be a first-round talent before multiple leg injuries blew up his senior year. A complete player with outstanding potential, he missed all but five games in 2010 and suffered another setback when he pulled up with a hamstring injury while running his 40-yard dash at the scouting combine. The fact that he still timed out at 4.4 seconds on that 40 was a bit of a flash to talent evaluators regarding Dowling's athletic potential. He finally got to work out for teams in early April, but injury concerns will probably drop him to the second round in a fairly deep cornerback class.
Justin Houston, OLB, Georgia
Houston was believed by most pundits to be a mid-to-late first-round prospect, based on his ability to get to the quarterback in both three- and four-man fronts. But news that Houston failed a drug test at the combine — and according to NFLDraftScout.com, that's his second substance abuse violation — will not help his draft stock at all. Character concerns will have evaluators looking more closely at on-field abilities, and the increasing concern that Houston might be a relatively one-dimensional player could have him moving into the early second round.
Christian Ballard, DE, Iowa
Ballard also failed a drug test at the combine, according to that same FOXSports.com report, and that's especially bad news for a player who was relatively underrated and went through the pre-draft process with a relative lack of buzz surrounding his name. The thought among many in the know is that Ballard created more opportunities for Clayborn on the Iowa defensive line than the other way around, but the specter of a failed drug test in an obvious high-scrutiny situation doesn't speak highly for situational awareness — and for NFL players, that attribute is just as important off the field.
Marcus Cannon, OT, TCU
A very sad story here — Cannon, a huge lineman who has impressed me on tape, was recently diagnosed with lymphoma when he underwent tests to clear up what turned out to be a false rumor that he had another form of cancer. The timing of the diagnosis is rotten. We can simply hope for the best for the young man, but the news may take the talented Cannon from the second round to anything from mid-rounds to undraftable depending on what we may not know.
Stefen Wisniewski, C, Penn State
The nephew of legendary former Oakland Raiders tackle Steve Wisniewski, the new generation of Nittany Lions alum was once thought to be a possible top-15 pick. It's not that Wisniewski's talent or game tape dropped per se, but the fact that he probably projects better at center than guard at the NFL level because he doesn't flash guard power could see him picked in the early-to-late second round. With so many tackles projected to go above him, Wisniewski is on the wrong side of a numbers game.