Sprained left shoulder for 49ers' Alex Smith

Alex Smith has not returned to the San Francisco 49ers' game against the Carolina Panthers.

Smith suffered an injured left shoulder while taking a sack Sunday. According to the 49ers, Smith suffered a sprained left shoulder and X-rays were negative. Smith's left arm is in a sling.

David Carr has completed 1 of 4 passes for 6 yards. Carolina holds a 13-10 lead entering the fourth quarter.