Mathieu's skills have never been the issue. A ballhawk while at LSU, Mathieu was the recipient of the 2011 Chuck Bednarik Award, which is given to the nation's top collegiate defender. He was later dismissed from LSU for violating team rules, and he entered a Houston rehab center for help managing his marijuana use. And thus, his draft stock plummeted. Still, if Mathieu can convince teams he can keep his behavior in check, he could be a late-round steal. Or he could be a first-round pick. In this draft, it's hard to tell. - Evan Hilbert, CBSSports.com
He made an immediate impact as a freshman in 2010, earning the backup job to Patrick Peterson in fall practices and playing in all 13 games, including one start at left cornerback. He led the SEC with five forced fumbles - the first glimpse at Mathieu's big-play flair. Despite his 5-foot-9 frame, Mathieu had a team-high seven pass break-ups as a freshman to go along with 8.5 tackles for loss, 4.5 sacks, three fumble recoveries and a pair of interceptions.
Mathieu closed out his first season in Baton Rouge by earning the Cotton Bowl Defensive Most Outstanding Player award by recording seven tackles, one tackle for loss, two forced fumbles, one fumble recovery, one interception, one sack and one pass breakup.
Nicknamed "Honey Badger," Mathieu burst onto the national scene in 2011. He led the team with 70 tackles, forced an SEC-best six fumbles and recovered five.
Mathieu's big-play ability was also evident on punt returns, as he ranked second in the nation with a 16.2-yard return. He was named the SEC Championship Game MVP against Georgia after he returned a punt 62 yards for a touchdown, posted four solo tackles and recovered a fumble.
Mathieu earned a trip to New York as a finalist for the Heisman Trophy, becoming the first Tiger to earn an invitation to the ceremony since Charles Alexander in 1977. He also won the Chuck Bednarik Award as the nation's top defender as year after Peterson won the honor.
Poised to build on that success in 2012, Mathieu was abruptly dismissed from the LSU program Aug. 10 for violating team policy - reportedly for multiple failed drug tests.
"This is a very difficult day for our team," LSU head coach Les Miles said. "We lose a quality person, teammate and contributor to the program. However, with that being said, we have a standard that our players are held to and when that standard is not met, there are consequences. "It's hard because we all love Tyrann. We will do what we can as coaches, teammates, and friends to get him on a path where he can have success. We are going to miss him."
Mathieu considered transferring to McNeese State and visited the school, but ultimately enrolled at LSU for the fall semester after a brief stay in a drug rehabilitation center.
Mathieu and three other former LSU football players - Jordan Jefferson, Karnell Hatcher and Derrick Bryant - were arrested Oct. 25 after police found drug-related materials in Mathieu's apartment along with marijuana. Mathieu was booked on charges of simple possession of marijuana and later released.
NFL scouts who were encouraged by Mathieu's decision to meet daily with former NBA player and head coach John Lucas, who battled drug addiction in the past, now had more off-field issues to weigh.
NFLDraftScout.com had projected him as a top-40 pick before his suspension. His value will depend on how teams judge his explanation of his off-field missteps.
Negatives: Lacks ideal height for the position and is quicker than he is fast, making him susceptible on longer throws. Highly aggressive and will bite on underneath routes. Possesses the suddenness to make up for a miss-step but does not have the elite straight-line speed to recover against a well-executed double-move and accurate pass. Trusts his instincts too much and can put his teammates in difficult positions by drifting to where he anticipates the quarterback will be going with the football. As such, cerebral NFL quarterbacks will be able to manipulate him with their eyes and potentially beat him over the top with accurate deep passes. Has a well-documented history of poor decisions off the field that could result in even more struggles given the money and notoriety he'll receive as an NFL player.
Compares To: Antoine Winfield, CB, Minnesota Vikings -- Like the 5-09, 180 pound Winfield, Mathieu has Pro Bowl potential due to his tenacity, instincts and physicality.