Big-name defensive players hurt draft stock with letdown seasons

After 11 weeks of columns focusing on prospects moving up draft boards, enough players to fill the first three rounds of next April's draft, its time to focus on the sliders. Here are 15 prospects, including some big-time college players, who have watched their draft stock fall since the college season began three months ago.

Vontaze Burfict, LB, Arizona State*: Possibly no player has dropped down draft boards faster this season than Burfict. He entered the campaign ranked as a potential top five pick, but his immaturity has cost him at least half a round, if not more. He's been consistently flagged for unsportsmanlike penalties, and it has cost his team dearly. Scouts say Burfict shows little in the way of controlling his temper, which has NFL decision-makers concerned.

Quinton Coples, DE, North Carolina: Coples was considered the top senior prospect in the nation by many scouts entering the season, but his play this year has been uninspired. He's flashed brilliance, but has shown little in the way of consistency. Initially considered a top-five pick, Coples could fall out of the draft's top 10 choices.

Devin Taylor, DE-OLB, South Carolina*: Taylor was another player who entered the season ranked as a potential early first round pick. He's taken a backseat to a pair of teammates, though -- freshman sensation Jadeveon Clowney and senior Melvin Ingram, who is rocketing up draft boards. Taylor, who is expected to enter the draft, has fallen into the middle of the first round.

Jared Crick, DE, Nebraska: Crick received first round grades prior to the season despite doubters in the scouting community. He totaled just a single sack with 3 tackles for loss before a torn pectoral muscle ended his season just five games in. He is now likely to fall out of the first round.

Billy Winn, DT, Boise State: NFL scouts believe Winn possesses first-round physical skills, but are concerned by his inconsistent play on the field. He's posted just 29 tackles, 6 tackles for loss and 1 sack in 10 games this year and has never been truly productive in college. Expect Winn to land somewhere in the middle of the second round next April.

Jeff Fuller, WR, Texas A&M: Fuller has struggled most of the year after being considered one of the top senior receiver prospects when the season began. The big-bodied receiver doesn't display natural pass-catching skills and drops too many catchable throws. Once ranked as a second-round choice, Fuller has fallen into the bottom half of the third frame and could drop even lower.

Bruce Irvin, DE-OLB, West Virginia: Scouts graded Irvin as one of the best pass-rushers in the land and a potential first-round pick after he registered 14 sacks in 2010. But he's posted half that amount this year as opponents have figured out his game. As a result, Irvin is no longer being mentioned as a top 32 selection.

Nick Toon, WR, Wisconsin: Toon is reliable, but has not displayed a dominant aspect of his game. Labeled a top-40 pick in September, Toon could drop into the third round unless he pulls off a sensational workout prior to the draft.

Brandon Lindsey, OLB, Pittsburgh: Lindsey was a pass-rushing terror at defensive end in 2010 and a highly rated prospect scouts project to rush linebacker in the NFL. But the Panther has struggled on a number of levels this season. Early in the campaign he looked lost when asked to play the linebacker position, and his production on the field has fallen below expectations. His play this season will end up dropping Lindsey at least one round in the draft.

Matt Reynolds, T, BYU: Reynolds bypassed last April's draft after suffering a shoulder injury and entered the season with high expectations from scouts. Thus far, though, he has looked soft and been a huge disappointment. Once considered a potential top-75 choice, Reynolds will now be a last-day selection.

Nate Potter/T/Boise State: Potter looked like a star early in his college career, but his play has regressed and many scouts think his best football is behind him. Graded as first-round material just two years ago, most scouts have stamped Potter with a fifth-round grade.

Tony Dye, S, UCLA: Dye was considered by many NFL scouts as a better prospect than former teammate Rahim Moore, the second round choice of the Denver Broncos last April. But Dye's play this season has been poor as he seems to lack instincts, giving up a fair number of big plays. He's dropped from a potential middle-round choice into the late part of the draft.

Ryan Lindley, QB, San Diego State: Lindley, whom I referred to as the most underrated prospect in the nation in August, has looked pedestrian all season. He stumbled early in the year against Michigan and never got his game on track. Lindley has struggled with his accuracy all season and as a result will drop into the late rounds of the draft.

Chris Owusu, WR, Stanford: Owusu possesses the physical skills necessary to start at the next level, but has been red-flagged with medical concerns. Suffering three concussions over a 13 month period, Owusu will fall into the very late rounds of the draft after initially being graded as a top-60 prospect.

Juron Criner, WR, Arizona: Criner has proved himself to be a game-controlling wideout throughout his college career. He possesses the skills to line up as a third receiver in the NFL. But personalities issues and concerns Criner is not "coachable" have made a big dent in his draft stock. There are whispers in the scouting community that Criner will fall into the late rounds of April's draft and could even wind up undrafted.