The CFL club told the veteran tailback Friday it won't be offering him a new contract. Cates is poised to become a free agent next week.

Also on Friday, the Riders signed running backs Kory Sheets, Louis Rankin and Demetrius Crawford.

The Riders acquired the six-foot, 213-pound Cates from Calgary prior to the 2007 season and helped Saskatchewan capture the Grey Cup despite a broken foot.

Cates, 32, was a CFL all-star in 2008 after rushing for 1,229 yards and 12 touchdowns. He ran for 1,054 yards in 2010 but registered 680 yards on the ground last season.

Over his six CFL seasons, Cates has rushed for 4,942 yards and averaged a solid 5.3 yards per carry. He has also scored 83 touchdowns.

The Roughriders also released offensive lineman Marc Parenteau and receiver James Robinson.