Quarterback Alex Smith #11 of the San Francisco 49ers gets hit by linebacker Jo-Lonn Dunbar #52 of the St. Louis Rams during a run in the first quarter on November 11, 2012 (PHOTO: GETTY IMAGES)
SAN FRANCISCO, CA - San Francisco 49ers quarterback Alex Smith left Sunday's game against the St. Louis Rams with a concussion.
Smith suffered the concussion late in the first quarter on a quarterback scramble. As he began to slide, he turned his back to linebacker Jo-Lonn Dunbar, who hit Smith around the neck area.
Smith stayed in the game temporarily and even threw a touchdown pass to Michael Crabtree in the second quarter.
Colin Kaepernick replaced Smith later in the frame.
The Sports Network