Adrian Peterson's status didn't change Saturday at training camp. The Vikings star running back remains on the Physically Unable to Perform (PUP) list. And he remains convinced that he will be in uniform and ready for action when the regular season opens Sept. 9 against Jacksonville at Mall of America Field.

During Saturday afternoon's practice, Peterson found a way to get in some work out of the backfield. By himself. With head athletic trainer Eric Sugarman calling specific plays, delivering handoffs and throwing Peterson short passes.

Peterson worked more on cutting and getting back into the flow of football-specific movements. And with no defense, he kept reaching the end zone and heading right back to the backfield for more.

Hey, it’s progress for Peterson, who continues to work on his leg strength but is now also focusing on shaking the rust off his running back moves and testing how his knee responds.

Said head coach Leslie Frazier: "That's what we're trying to get done -- just to simulate somewhat some of the things he would do in drill work to see how he responds. And one of the keys is to see what happens the day after. So we'll keep monitoring it, keep adding a little bit more and make a decision at some point."

Still, there's no definitive timetable to estimate when Peterson may return to practice. As for the possibility that he might be able to play in any of the Vikings' preseason games as a tune-up for the regular season?

"Ideally, if we're going to try to see him in the first game of the season, you'd like for him to get some work in the preseason at some point," Frazier said. "Now will that happen? I don't know. We'll see how he progresses. But ideally, you'd like to see him get some carries at some point in the preseason just for his benefit where he can gain some confidence and get a feel for where he is and where he needs to be by the first game of the season."