SEATTLE -- Tight end Vernon Davis sustained a concussion late in the first quarter and was ruled out for the remainder of the game.
Davis, who earlier caught a 27-yard pass from quarterback Colin Kaepernick, went up for a catch near the goal line when Seattle Seahawks safety Kam Chancellor leveled him with a huge -- and illegal -- hit.
Chancellor launched himself at Davis and was penalized 15 yards for striking a defenseless player in the head area.
Davis was immediately removed from the game and evaluated by 49ers team physical Dr. Dan Garza, a leading concussion researcher at Stanford. The 49ers determined Davis sustained a concussion, preventing him from returning to action.
Delanie Walker and Garrett Celek replaced Davis at tight end for the 49ers. Davis must receive clearance from an independent neurologist, as well as the 49ers' medical staff, in order to return to action for the regular-season finale next week against the Arizona Cardinals.