Willis McGahee was hurt in the second quarter Sunday. (Jack Dempsey / AP)

Updated at 3:10 p.m. with MRI result

An MRI on Willis McGahee‘s right knee showed that the Denver Broncos’ running back tore his medial collateral ligament in the Broncos’ victory over the San Diego Chargers on Sunday.

McGahee, who rushed for 55 yards on seven carries Sunday, was injured early in the second quarter, and is expected to be out 6-to-8 weeks (essentially the rest of the regular season), according to the Denver Post. The plan for McGahee, Coach John Fox said, calls for “rest and rehab” and McGahee “will not be on [the injured reserve list].”

“He’s very disappointed,” Fox said. “He’s a fast healer. He’s a tough guy, and right now at this point we wouldn’t want to prolong it that far [to the season-ending IR].”

Possibilities at running back include rookie Ronnie Hillman, Lance Ball and Knowshon Moreno.

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