Garner fell short of hitting incentives that would have automatically voided the final year of his contract.
Garner was scheduled to make $4.227 million this season. He averaged 4.6 yards on 120 carries and was third on the team with 48 receptions.
Garner turns 32 Friday, but he should draw a plenty of interest in free agency. He probably will draw looks from the Bucs, Lions, Cowboys and possibly the Super Bowl champion Patriots.
Garner, nicknamed "IO" (Instant Offense) by former Raiders coach Jon Gruden, has played for the Eagles, 49ers and Raiders in his 10-year career. He gained a career-best 1,229 yards on the ground for the Niners in 1999.