After a week of encouraging signs for Alex Smith, the San Francisco 49ers quarterback needs more time to heal from the concussion he suffered eight days ago and will not start against the Chicago Bears on Monday night.
ESPN's Chris Mortensen reported Monday morning that Smith was unable to gain clearance from a neurologist, according to sources, meaning Colin Kaepernick will start against Bears backup Jason Campbell, filling in for a concussed Jay Cutler.
NFL.com's Albert Breer later confirmed, citing a 49ers source, that Smith will not play. "He tried, just couldn't pass the final hurdle," the source said. "No one wanted to take an unnecessary chance."
This bucks the flow of reports coming out of the Bay Area over the weekend describing Smith as someone gearing up to play. He practiced for four consecutive days in a black (non-contact) jersey and was set to undergo a "contact" test Sunday.
Doctors either weren't encouraged by the results of that test or where they estimated Smith's health to be with the game against the Bears less than 12 hours away.
UPDATE: The 49ers officially announced that Smith is out after being evaluated.
Kaepernick started for the Niners.
Follow Marc Sessler on Twitter @MarcSesslerNFL.