San Francisco 49ers quarterback Alex Smith will not play Monday night against the Chicago Bears because he was unable to get clearance from a neurologist one week after suffering a concussion, according to sources.
Colin Kaepernick will start in Smith's place in a game that also will feature Jason Campbell as the Bears' starter because Jay Cutler has been declared out, also because of a concussion.
Smith, who is ranked third in the NFL with a 104.1 passer rating, practiced in a noncontact black jersey last week and took part in most of the drills involving the first-team offense.
Smith, who has made 28 consecutive starts, was injured during the first half of a 24-24 tie with the St. Louis Rams in Week 10 and left the game midway through the second quarter.
Kaepernick replaced Smith after the injury and was 11-of-17 for 117 yards and rushed for 66 yards and a touchdown against St. Louis.
Information from The Associated Press was used in this report.
