The Niners will have to take on the Bears tonight without the services of QB Alex Smith according to Chris Mortensen of ESPN.
The report says that Smith was not cleared by an independent neurologist, and therefore it will be Colin Kaepernick starting for the Niners against Chicago.
The game will feature the backup for the Bears at QB as well, as Jason Campbell will go for the Bears for the injured Jay Cutler.
Cutler is out because of concussion symptoms that he suffered when hit in the helmet by Texans linebacker Tim Dobbins last Sunday night. Campbell replaced Cutler behind center to start the third quarter.
Last week vs the Rams, Kaepernick played the entire second half and overtime, going 11 of 17 passes for 117 yards and rushing for 66 yards and a touchdown.