Arizona selected Wells with the No. 31 overall pick of the 2009 NFL Draft out of Ohio State, but Wells' Cardinals career never lived up to first-round expectations. Wells had a tumultuous relationship with then-head coach Ken Whisenhunt, leading to a lack of playing time. Wells' best season in Arizona came in 2011, when he received a career-high 245 carries, and rushed for a career-high 1,047 yards and 10 touchdowns.
Despite the strong 2011, injuries and a clash with Whisenhunt kept Wells off the field in 2012. Wells appeared in just eight games after being given the injured reserve with a designation to return tag after Week 3, when Wells suffered a toe injury.
Still, Wells finished 2012 with just 88 carries for 234 yards, averaging an anemic 2.7 yards per carry. Arizona decided to part ways with Wells, despite Wells only having a base salary of $1.4 million in 2013.
Wells' Cardinals career ends with 625 carries, 2,471 rushing yards and 24 rushing touchdowns over four seasons.