Minnesota Vikings running back Adrian Peterson will not need surgery on his sprained right foot, but is unlikely to play on Sunday against the Philadelphia Eagles, according to a person with knowledge of the situation.

Peterson sustained a mid-foot sprain in the second quarter on Sunday against the Baltimore Ravens, as linebacker Arthur Brown tackled him while he tried to stretch for a first down. X-rays were negative on Peterson's foot, a MRI showed no structural damage or risk of a Lisfranc injury, and Peterson said on Monday afternoon he planned to play Sunday. But he was still scheduled to undergo a CT scan on his foot, and the Vikings planned to send the results of Peterson's medical exams to a foot specialist.

When the Vikings got the results on Monday evening, they determined Peterson would have to spend time in a walking boot and prove he can run once he gets out of the boot, according to the source.

It remains to be seen whether that will happen yet this season. Dallas Cowboys running back DeMarco Murray missed six weeks with a mid-foot sprain last season, and Jacksonville Jaguars running back Maurice Jones-Drew is averaging a career-low 3.5 yards per carry this season after sustaining a Lisfranc injury in 2012 and spraining his foot again this year.