This just showed up on The Sports Network's site.
Ashburn, VA (Sports Network) - Washington Redskins running back Clinton Portis will not play Sunday against the Saints due to lingering effects from a concussion suffered November 8 against the Falcons.
Portis, who has missed the last three contests, has not seen the practice field since the injury. With backup Ladell Betts out for the season due to a knee injury, Rock Cartwright figures to get his second straight start.
The 28-year-old Portis has a team-high 494 yards on the ground but just one rushing score in eight games this season.