Alex Smith has been knocked out of the San Francisco 49ers' game against the St. Louis Rams with a concussion.
Smith scrambled and started to slide before turning his back late, and linebacker Jo-Lonn Dunbar barreled into his neck area with 1:10 left in the first quarter Sunday. Smith briefly grabbed his facemask and grimaced but stayed in the game, throwing a 14-yard touchdown pass to Michael Crabtree in the second quarter.
Colin Kaepernick replaced Smith on San Francisco's next possession. Smith sat on the bench next to 49ers athletic trainer Jeff Ferguson and other trainers before walking to the locker room just before halftime.
Smith was 7 for 8 for 72 yards and the touchdown. The 2005 No. 1 overall draft pick started every game for the 49ers last season.
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