Portis out with concussion

Running back Clinton Portis suffered a concussion in the first quarter of the Redskins' game at Atlanta and will not return to the game, the team announced early in the second quarter. Portis, the Redskins' leading rusher, broke through the left side of the line on a second-and-12 play from the Atlanta 36 yard line. Center Casey Rabach was called for holding on the play, and Portis fell hard to the turf as he was tackled by Atlanta defensive backs Chevis Jackson and Thomas DeCoud. Portis lay face down on the turf and motionless for a bit. He then rolled over and was eventually helped up and off the field. He carried four times for four yards in the first quarter. Ladell Betts will see most of the action the rest of the way, though third-stringer Rock Cartwright caught a pass late in the first quarter.