Joe Staley injury: 49ers LT leaves game with concussion

The San Francisco 49ers will be without left tackle Joe Staley for at least the rest of Sunday's game after the All-Pro left the field with a concussion. Staley, who made his first Pro Bowl and All-Pro team last year, is the anchor to the Niners' offensive line that has done a bang-up job of protecting quarterback Alex Smith so far in 2012.

Staley, a first-round draft pick in 2007, has had some problems with injuries over the years, missing seven games in 2009 with a knee injury, but has generally been healthy and productive. With new scrutiny on head injuries — and the 49ers wanting to protect their prized offensive lineman — expect head coach Jim Harbaugh and Co. to take every precaution with Staley's injury.

Expect either Joe Looney or Leonard Davis to fill in for Staley in his absence. The 49ers are very thin at tackle — they don't list any backups for Staley or right tackle Anthony Davis on the depth chart, and have just one backup each for the center and guard spots.