SEATTLE –- Running back Frank Gore left Sunday's game in the second quarter and was diagnosed with a concussion, the 49ers announced.
Gore sustained his injury while he made a block attempt on Seattle Seahawks linebacker Bobby Wagner after a short pass to fullback Bruce Miller.
He remained on the field for several moments near the 49ers sideline. Then, Gore left the field and went to the locker room with members of the team’s medical staff. Gore broke into a jog.
Gore must pass the NFL's protocol on concussions in order to receive clearance to play Saturday against the San Diego Chargers.
Gore had 29 yards on 11 carries, including a 10-yard touchdown run that gave the 49ers a 7-3 lead in the second quarter.
Rookie running back Carlos Hyde had 45 yards rushing on three attempts in the first half. Alfonso Smith is the only other 49ers’ running back on the roster.
