Guy Whimper injury: Steelers use third left guard of the game, Cody Wallace, after Whimper hurt in third quarter

After the seventh play of the Steelers' 2013 season, their offensive line had remained relatively injury-free.

Sunday, amid a shellacking at the hands of the host Oakland Raiders, the Steelers lost their second left guard of the game. Guy Whimper went down in the middle of the Steelers' opening drive of the half, trailing 21-3. He replaced Ramon Foster, who is out of the game with a concussion.

Wallace, a free agent pick-up in training camp, has not played prior to Sunday.

The Steelers are in the process of an extended drive against a tough Raiders defense that's severely limited them to this point in the game. It may be too little, too late, particularly with a Steelers defense that's well on its way to challenge the Steelers' all-time rushing yards allowed mark.

Not sure what it is, but it can't be a whole lot higher than 360, which is what Oakland is on pace to get.