Vikings' Zimmer hopeful Peterson's injury is minor

An MRI will determine the full extent of Adrian Peterson's knee injury Monday morning, but Minnesota Vikings head coach Mike Zimmer doesn't seem overly worried about his offensive star missing much time.

Peterson left in the third quarter of his team's Sunday night 17-14 victory over the Green Bay Packers. He appeared to be in a great deal of pain, favoring his right knee. At the postgame press conference, Zimmer told reporters he didn't know the extent of the injury, but had some more positive comments later on.

"He might miss a week. I don't know if he will or not," Zimmer said, according to ESPN's Ben Goessling. "Whatever it was has calmed down now, so we'll see."

The veteran running back was seen leaving the locker room on crutches. The injured knee is not the same one that Peterson tore ACL and MCL ligaments in back in 2011.