San Francisco 49ers starting quarterback Alex Smith left the 49ers' Week 10 contest against the St. Louis Rams in the second quarter, after sustaining a concussion on a fourth-and-1 quarterback sneak.
Rams linebacker Jo-Lonn Dunbar dished out the hit that concussed Smith.
San Francisco's next contest is a Week 11 date against the Chicago Bears on Monday Night Football, so the 49ers and Smith will have an extra day to evaluate Smith's symptoms and health before making a decision on whether or not Smith is able to play.
Smith will have to pass a series of concussion tests in order to gain medical clearance for the game, and his status likely won't be updated until the end of the week. Colin Kaepernick will start at quarterback if Smith is unable to go on Monday night.