MANKATO, Minn. -- The Minnesota Vikings have placed running back Adrian Peterson on the active physically unable to perform list to start training camp.

The move was expected, considering the team's preference to be cautious with its franchise player and his comeback from reconstructive surgery on his left knee. Peterson can come off the PUP list at any time, but he can't take part in drills with the team until then. He still counts against the 90-man roster.

Coach Leslie Frazier said Friday that Peterson put up a fight but the decision is best for the team.

"Ultimately I knew how the conversation was going, that it wasn't going to go my way no matter what I thought," Peterson said. "But I understand the decision."

Peterson said he feels like he's ready to start the regular season.

"The one thing I'm missing is being out there and actually going through the actual football activities with guys diving at your legs and making cuts and things like that," he said. "That's something you can't imitate off to the side by yourself."

Two other offensive players competing for backup spots were placed on the active non-football injury list. Wide receiver Stephen Burton has a jammed toe, and tight end Mickey Shuler has a sore heel.