Redskins running back Clinton Portis revealed on Tuesday that he suffered a sprained MCL in his right knee against the Steelers on Nov. 3. "Thursday night and Friday, it started getting worse, so I came in, and they said MCL sprain, second degree," Portis said. "As of right now, I can't straighten it out, and I started bending it today. Hopefully by the end of the week - we'll have five days - I'll be right." Portis did not practice Monday, and Washington coach Jim Zorn listed him as "questionable" and "50-50" for Sunday's game against the Dallas Cowboys.