Robert Griffin III was knocked out of the Redskins 24-17 loss to Atlanta Falcons in the third quarter Sunday, and did not return to the contest. According to head coach Mike Shanahan, Griffin suffered a mild concussion on the hit by Atlanta linebacker Sean Weatherspoon. Via Rich Campbell of the Washington Times:

Mike Shanahan: RG3 suffered a mild concussion. He didn't know the score or what quarter it was after the hit. #Redskins

— Rich Campbell (@Rich_Campbell) October 7, 2012

Griffin was injured on the play below, as his feet came out from under him on a scramble just as Weatherspoon's shoulder made impact with the rookie's helmet:

Griffin finished the day 11 of 17 for 95 yards, with no touchdowns or interceptions. Backup quarterback Kirk Cousins entered the game, and after completing a 77-yard bomb to Santana Moss to put Washington up 17-14, the backup quarterback threw two interceptions, finishing his day five of nine passing for 111 yards.