Peterson told ESPN's Josina Anderson that he suffered a Grade 1 high ankle sprain and Grade 2 low ankle sprain in Sunday's loss to the San Francisco 49ers. He underwent an MRI on Monday but told reporters he plans on playing vs. the Minnesota Vikings on Thursday.
"I feel pretty confident," Peterson said. "Yesterday was rough. I didn't really know. I woke up this morning feeling really good; the swelling had gone down tremendously. Two more days to heal and do the necessary things this training staff put me through -- and the home remedies I do as well -- I should be good."
Peterson, who ran for 81 yards on 20 carries against the 49ers, injured his ankle while fumbling in the 9-0 loss. The Redskins need Peterson because running back Chris Thompson missed last week and hasn't practiced this week because of a toe injury.
Peterson, who has rushed for 199 yards the past two weeks combined, said facing his former team also provides a boost of adrenaline.
"Of course, of course it does," he said. "If it was any other team, I'd be just as motivated, but maybe not as much. Of course I want to play against Minnesota. I was there for 10 years; 98% of the guys on the defense, I played with those guys."
Peterson played with the Vikings from 2007 to 2016 before leaving as a free agent. He signed with New Orleans in 2017 and played his first game with the Saints at Minnesota, rushing only six times for 18 yards.
Peterson rushed for 11,747 yards and 97 touchdowns with Minnesota.
"It was always real love," he said of his relationship with the fans. "I was there for a decade, and still to this day, I have fans that come to Redskins games that are diehard Vikings fans because they're Adrian Peterson fans. The love is always going to be there."
Wendell Smallwood is the No. 2 back behind Peterson.