Dallas Cowboys running back DeMarco Murray sprained the medial collateral ligament (MCL) in his left knee in Week 6, and it appears that he will be out this week. ESPN Dallas.com cites a source as saying Murray is unlikely to play in Week 7, but did not offer a formal timetable.
MCL sprains vary in how much time they cost a player, depending on the severity of the injury. Buffalo Bills running back Fred Jackson sprained his MCL in Week 4 and played the following week. Actually, Jackson suited up just four days later for the Bills' Thursday night game, and maintained the lead back role as teammate C.J. Spiller was compromised with an ankle injury. On the other hand, Ravens wide receiver Jacoby Jones just played in his second game of the season Sunday, five weeks after injuring his MCL in Week 1.
Clearly, Jackson suffered a mild or Grade 1 injury (where there is no visible structural damage, but there is inflammation and pain in the area), while Jones most likely suffered a Grade 2 (moderate) sprain, where there are damaged fibers within the ligament but not a complete tear. The more substantial the damage is to the tissue, the longer the recovery.
Murray could wear a brace with medial and lateral struts to protect against stresses to the side of the knee, presuming he is healthy enough to perform. Ultimately as a running back, he needs to be able to plant and cut to the inside on that knee without hesitation. Murray desperately wants to show he can get through a season without being limited by injury after missing multiple weeks each of his first two years in the league. Regardless of his past history, Murray needs to be able to run effectively to be on the field, while not placing himself at undue risk of further injury and that will be the determining factor as to when he makes his return. At this point, he should not be counted on for Sunday's matchup against the Eagles.