LANDOVER, Md. -- Washington Redskins running back Clinton Portis was unable to practice Monday because of a sprained knee, and coach Jim Zorn said Portis is "50-50" for Sunday night's game against the Dallas Cowboys.
Portis' absence from a major game against a division rival would be tough to overcome. He's been the engine of the offense, and his primary backup, Ladell Betts, has missed the last three games with a more severe knee injury. Shaun Alexander, signed after Betts got hurt, has contributed little, and the other running back on the roster, Rock Cartwright, is heavily involved with special teams.