Ladell Betts suffered a left knee injury during the first quarter of Sunday’s game against the Cowboys and will not return, leaving the Redskins without their top two running backs.
Betts was making his second consecutive start in place of Clinton Portis, who hasn’t played because of a concussion. Betts rushed for 114 yards on 26 carries last week in a 27-17 victory over the Broncos.
Eighth-year pro Rock Cartwright took over for Betts on Sunday, with Quinton Ganther serving as the backup.
Redskins CB DeAngelo Hall left the game with a knee contusion, but he returned in the second quarter.