"Vikings running back Adrian Peterson, who suffered a serious high ankle sprain during the Vikings' 27-21 loss to the Raiders, said Wednesday he expects to play against the Falcons on Sunday.

Peterson, who was in a walking boot but not limping Wednesday, expects to practice by Friday and be ready to go Sunday.

The final decision on whether Peterson will play will be made by coach Leslie Frazier, who didn't dispute what Peterson said.

X-rays taken after the game and an MRI on Monday were encouraging, which means Peterson won't be out too long. He said he actually wanted to go back in the game on Sunday.

"I just got my ankle caught up on a defender and it got twisted up pretty bad," Peterson said. "[It's] just my mentality. I'm always going to come out and see what I can do. I guess it was just me trying to convince myself that I could go back out, but ultimately I couldn't.""