A first-round pick in 2009, Wells showed flashes of the brilliance he had at Ohio State, but has only played one full season -- his rookie year.
Wells eclipsed 1,000 yards and scored 10 touchdowns in 2011, but was limited to eight games last season due to a turf toe injury. Last season, he ran for 234 yards and eight touchdowns as part of what was the worst offense in the NFL.
The move leaves the team thin at running back, with even more injury-plagued Ryan Williams the main returner. Williams missed all of his rookie 2011 season and most of last season with injuries.
Among the possible targets for the team under newly promoted general manager Steve Keim is Reggie Bush.
Wells has 2,471 yards and 24 touchdowns rushing, with 28 catches for 293 yards in 51 career games. He set a franchise record of 228 yards rushing against the St. Louis Rams in 2011, the only season in which he topped 1,000 yards. But he played in just eight games last season, averaging a career-worst 2.7 yards per carry.
The 6-foot-4, 229-pound Wells was envisioned as a power running back to anchor Arizona's offense but injuries and inconsistent play kept him from being a consistent threat. He had only three 100-yard rushing games in his four seasons in the desert.
After gaining four yards in three carries against Chicago in Arizona's next-to-last game of last season, Wells forecast his own demise with the organization when he indicated that, in Arizona's finale against San Francisco, he would be auditioning for the NFL's other 31 teams. Then-coach Ken Whisenhunt didn't take kindly to the remark and benched him for the entire game.
Coming off their Super Bowl season, the Cardinals selected Wells out of Ohio State with the 31st pick (out of 32) in the first round in 2009. He reportedly was due a $1.3 million signing bonus this week.
He joins a growing list of Cardinals released in recent days that includes five-time Pro Bowl strong safety Adrian Wilson, last year's starting cornerback William Gay, wide receiver Early Doucet and inside linebacker bust Stewart Bradley.
"Just been informed that I'll be released today," Wells said in a tweet. "Would like to thank the Cardinals organization for (giving) me the chance to live out my Dreams."
A moment later, he added, "The best is yet to come!!!"
With Keim in his new job and with a new coach in Bruce Arians, just where the Cardinals are going in the next few days of free agency is a mystery.
Running backs aside, the biggest question remains at quarterback. Kevin Kolb is due a $2 million roster bonus this week and, with a salary scheduled to hit $9 million in the coming season, he almost certainly won't return unless he restructures the deal.
Arizona also released running back Fozzy Whittaker off its practice squad.