Seahawks safety Jamal Adams headed to the locker room before the first half ended.
The team now reports that Adams will not return with a shoulder injury. He returned to the sideline in street clothes for the second half.
Ryan Neal has replaced him.
Adams finished with four tackles.
Seahawks defensive tackle Bryan Mone is questionable to return after injuring a knee. Mone has one tackle.
49ers running back Elijah Mitchell took a hard hit from Darrell Taylor in the third quarter. Mitchell was evaluated for a concussion and cleared to return.
He is back in the game.
Mitchell has 18 carries for 54 yards and a touchdown.