Peterson was carted off the sideline during the second quarter of last Sunday's 27-21 loss to the Oakland Raiders. Vikings coach Leslie Frazier told reporters Monday that Peterson sustained some ligament damage and will be in a walking boot for a few days. Peterson isn't expected to even try to practice until Friday to determine if he'll be able to play against the Falcons.
"The good news is there is nothing more serious than that, the fact that it is an ankle sprain and he'll recover from it," Frazier said. "It's just the matter of the amount of time he'll miss, but we'll have a better indication towards the end of the week."
Frazier wouldn't commit to the idea that Peterson would have to be 100 percent healthy in order to play, saying the team would monitor his progress. Frazier added the Vikings' record wouldn't be a factor in the decision.
"We don't want to put him at risk," Frazier said. "You know how valuable he is to our team and our franchise. We'll monitor where he is and try to make a good decision on what's best for him and what's best for our team as well."
Frazier said during his postgame news conference Sunday night that Peterson had no fractures or broken bones in the leg. Frazier added that Peterson has a Grade 1 sprain, the least severe of the three categories.
"That's not in my DNA," he said, according to the St. Paul Pioneer Press. "I'm going to try to get back as fast as I can, and God willing, I'll be up and ready to run this weekend."
The Associated Press contributed to this report.