Both Culliver and Martin had been listed as questionable on the injury report, both with knee injuries. Right tackle Anthony Davis had already been ruled out with a concussion leaving the 49ers minus two starters on the offensive line. Along with Culliver, the 49ers will also be without backup cornerback Tramaine Brock leaving San Francisco thin in the secondary.
Backup tight end Cooper Helfet was inactive for a third straight game for Seattle with an ankle injury. He was the only Seattle player in question because of injury. Center Max Unger was inactive after being doubtful with ankle and knee injuries. Seattle is hopeful Unger will be able to return next week at Arizona.