Dallas Cowboys starting defensive end Marcus Spears has a grade two sprain of the medial collateral ligament in his left knee, Todd Archer of the Dallas Morning News reports.

Spears' injury will not require surgery, but will sideline him for 4-to-6 weeks, putting his availability for Dallas' September 12 season-opener against the Washington Redskins in jeopardy.

Jason Hatcher is the obvious choice to replace Spears, but Archer notes that he's been slowed by a hyperextended elbow. Marcus Dixon and Stephen Bowen will also be in the mix at right defensive end.