Selected out of Illinois by the Pittsburgh Steelers in the first round (No. 23 overall) of the 2008 NFL Draft, Mendenhall missed most of his rookie season with a shoulder injury before assuming the lead back role in the Steelers' backfield from 2009 through 2011. Over that span, Mendenhall ran for 3,309 yards with 29 touchdowns, establishing career highs in 2010 with 1,273 yards and 13 touchdowns.
Mendenhall was well on his way towards a third consecutive 1,000-yard season in 2011 when he suffered a torn ACL in a 13-9 win over the Cleveland Browns in the regular season finale. Mendenhall's injury kept him out of the first month of the 2012 regular season and in six games, including four starts, he ran for 182 yards on 51 attempts. Mendenhall struggled with ball security and was slated to be inactive for a Dec. 9 home game against the San Diego Chargers. Mendenhall did not show up for the game and was suspended by the team for one week.
The 5-foot-10, 225-pound Mendenhall will compete with 2011 second-round pick Ryan Williams for carries in the Cardinals' offense. Williams, who has battled knee and shoulder injuries over his first two seasons in the NFL, averaged just 2.8 yards per carry last season, so Mendenhall has a legitimate shot to earn a starting role and perhaps cash in on the 2014 free agent market.