A third-round pick out of LSU, the "Honey Badger" arrived in Arizona with a reputation for being incredibly talented and effective on the field but not necessarily on the right path off it.
Having spent the previous year away from football after being dismissed from his college team, Mathieu was as big of a question mark as you could find in the draft.
Mathieu collected 68 total tackles, two interceptions, one forced fumble, one sack and nine passes defended in just 13 games, as his season was cut short due to knee injuries suffered while returning a kick against the St. Louis Rams late in the season.
He did enough in his brief stint to be looked at as part of the team's future, and according to NFL.com's Bucky Brooks, is the ninth-most dynamic safety in the entire league.
The "Honey Badger" is the prototypical nickel defender that every defensive coordinator covets. Mathieu is an athletic safety with corner-like cover skills and a knack for playmaking. He is comfortable aligning anywhere, but he's at his best when deployed near the line of scrimmage as a lurking extra defender against the run or a sneaky rusher on passing downs. He routinely creates turnovers and makes disruptive plays all over the field. Mathieu blew out his knee last December, but if he can return to form, the second-year man has the natural ability to continue revolutionizing how defensive coordinators use nickel safeties.
When Mathieu returns to the field, he will be part of a revamped secondary that includes three-time Pro Bowlers Patrick Peterson and Antonio Cromartie as well a 2014 first-round draft pick Deone Bucannon.
Expected to be one of the team's strengths, it's a group that is not short on speed or playmakers.