49ers quarterback Alex Smith will not play Monday night against the Bears, according to sources in a report by ESPN.com's Chris Mortensen. A neurologist reportedly would not clear Smith a week after he suffered a concussion against the Rams.
Smith suffered the concussion on a hit by Rams linebacker Jo-Lonn Dunbar in the second quarter. Dunbar was not fined for the hit.
Smith appeared close to playing after reportedly taking first team reps -- while wearing a black no-contact jersey -- during practice last week. Smith is ranked third in the NFL with a 104.1 passer rating and has started 28 consecutive games.
Colin Kaepernick will make the first start of his NFL career in Smith's absence. The backup was 11 of 17 for 117 yards, and rushed for 66 yards and a touchdown in relief of Smith against the Rams.