Attempting to come back following a serious lower-back injury, Joe Riggs (Pictures) was scheduled to fight Mike Gates (Pictures) on Saturday in Halifax, Nova Scotia.

The Phoenix-based middleweight, however, remained home Thursday because, according to the fighter, the Washington Department of Licensing for Professional Athletics declined to clear him due to insufficient evidence that he was medically fit to fight.

Fighting Cory Devela (Pictures) on Feb. 23 in Tacoma, Wash., Riggs was thrown hard to the floor when his weakened back gave out on him. Riggs (27-10, 1 NC) was carried out on a stretcher and dealt with what he described as searing pain before undergoing a procedure to freeze three nerves in his spine.

Sherdog.com has learned that TJ Grant (Pictures) will replace Riggs in the Phoenix Fight Promotion 2 headline bout.