San Francisco strong safety
Michael Lewis has sustained his third concussion of the season, going down during the 49ers' game against Atlanta early in the third quarter trying to tackle Michael Turner.
Lewis, who sustained two concussions during an 11-day span in the preseason, could be sidelined for a prolonged period.
He led with his helmet on the hit Sunday and was face down on the field for several minutes while being examined.
The 29-year-old Lewis, a Pro Bowl selection in 2004 with Philadelphia, is in his eighth NFL season and third with San Francisco. He ranked third on the team with 118 tackles in 2008.
San Francisco 49ers' Michael Lewis sustains third concussion of season - ESPN