The move leaves first-round choice Knowshon Moreno to challenge veterans LaMont Jordan and Correll Buckhalter for the starting job. In an effort to rebuild a tailback position marked by injuries in 2008, Denver signed veterans Jordan, Buckhalter and Arrington as unrestricted free agents.
Arrington signed a four-year, $10 million contract on March 4, but he had undergone knee surgery a month earlier and was never fit to participate in offseason camps and organized team activities.
Arrington, 26, was a second-round draft choice of the Arizona Cardinals in 2005. The former Cal star suffered a series of injuries in Arizona that kept him from reaching his physical potential and he rarely demonstrated the kind of explosiveness and speed of his college career.
After his rookie season, when he carried 112 times, Arrington was used mostly as a reserve tailback and kick returner.
In 58 appearances including eight starts, Arrington rushed 183 times for 654 yards and three touchdowns. He also caught 91 passes for 693 yards and two touchdowns. Arrington returned 114 kickoffs for 2,694 yards and two touchdowns. He was the Cardinals' principle kickoff returner in 2005 and '08.
Len Pasquarelli is a senior writer for ESPN.