Portis has sprained MCL

Washington Redskins running back Clinton Portis revealed Tuesday he sustained a second-degree sprain of the medial collateral ligament in a Nov. 3 loss to the Pittsburgh Steelers.

During his weekly segment on ESPN 980’s “The John Thompson Show,” Portis said the injury to his right knee worsened late last week.

“Thursday night and Friday, it started getting worse, so I came in, and they said MCL sprain, second degree,” he 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 coach Jim Zorn listed him as “questionable” and “50-50” for Sunday’s game against the Dallas Cowboys.

A grade 2 sprain of the MCL is an incomplete tear of one of the knee’s four major ligaments and could require a recovery time of three to four weeks. Reserve running back Ladell Betts sustained a sprained MCL (though which degree wasn’t documented) in the Redskins’ loss to St. Louis on Oct. 12 and has yet to return to practice.

Portis was injured on a hit by Steelers safety Troy Polamalu in the first quarter, but he quickly returned to the game and finished with a season-low 13 carries for 51 yards. He ranks second in the league in rushing yards (995) and third in attempts (200).

Betts averaged around 18 snaps and six carries in six games before his injury.

“I’m getting close,” he said Monday. “I’m just worried about how it’s going to feel [Monday] and feel [Tuesday] after I run on it.”

Said Zorn: “He had a great workout [Monday]. We’ll try to inject him into some portions of practice Wednesday. … I can’t say I expect [Betts to play]. He’ll tell us verbally and by the way we watch him move whether he’s ready to go.”

If Portis and Betts can’t play, Shaun Alexander and Rock Cartwright would assume the duties. Alexander has 10 carries in three games since joining the Redskins after Betts’ injury, and Cartwright has four rushes. Fullback Mike Sellers is the other healthy back.

Portis, whose practice time before the Pittsburgh game was limited by hip and ankle injuries, missed the 2007 preseason with right knee tendinitis.