Peterson, who rushed for 96 yards in the Redskins' opening win over the Arizona Cardinals, said he is not ready to retire any time soon.
"Three to four more years would be ideal," Peterson said. "Not to say it hasn't been done before, but not at a high level. So of course I plan on playing three to four more years, and I plan on playing those years at a high level as well."
Peterson moved into 10th place on the NFL's career rushing list Sunday, surpassing Jim Brown, and now has 12,372 yards, along with 100 rushing touchdowns. He trails Tony Dorsett by 367 yards for ninth place, and he needs 5,984 yards to surpass Emmitt Smith as the all-time leading rusher.
That would be the ultimate accomplishment for Peterson, along with winning a Super Bowl title.
"The best player ever to play is my mindset," Peterson said. "Being able to sit back and say I had a great time playing the game I love and I won a world championship and I was the best at my position."
Among the modern-era running backs in the Pro Football Hall of Fame, three were still playing at age 35: Smith (35), John Riggins (36) and Marcus Allen (37). Riggins -- the only one to top 1,000 yards in a season at 35 -- rushed for a combined 2,586 yards for the Redskins at ages 34-35.
In the previous two years, thanks largely to injuries, Peterson rushed for a combined 601 yards. He was traded by New Orleans to Arizona in October 2017 -- his season was shortened by a neck injury -- and then remained unsigned until Washington called in mid-August.
That hasn't stopped Peterson from saying he could still be the best running back in the NFL.
"Yeah, definitely," he said. "Being out two years, but coming off the injury in Minnesota and the injury last year, of course there's a lot that I have to prove in order to be able to show that. Inside, I know that I feel I am. It's just about doing it for a full season."
Peterson said he'll know when to eventually retire.
"If my body starts acting up or I'm not feeling like I still have the burst, or the power, then my body will tell me that," Peterson said. "I'll recognize it for what it is and go from there. But I haven't experienced that yet."
Nor has he lost any motivation.
"I'm not going to lie, I definitely enjoyed not being in training camp," Peterson said. "But yeah, I think that's the No. 1 factor. You must have that motivation; you must have that passion, that love for the game.
"Brett Favre was a perfect example coming into Minnesota that 2009 year, and man, 'Oh he's this, that, and the other,' but that guy, he played with so much passion. He was the last one to leave the building, the first one there, and the way that he practiced pretty much set the tempo. He was full speed ahead every play."