The last time Adrian Peterson visited FedEx Field in Landover, Md., he writhed on the turf, as other players knelt and prayed. He rode the medical cart off the field, knowing there was a "99.9" percent chance he had torn ligaments in his left knee.

He sat in the locker room, hearing cheers as distant echoes, already anticipating months of tedious recovery.

On Dec. 24, 2011, at the lowest point of his professional career, Adrian Peterson called over Jeff Anderson, the Vikings director of corporate communications.

Peterson had noticed a kid wearing his jersey behind the bench. The kid, Keenan Wynn, had hung a banner listing Peterson's autograph as one of his Christmas wishes.

"Mr. Anderson came out in the fourth quarter and said, 'Excuse me, do you mind if I borrow that jersey for a moment?'" said Dr. Michael Wright, who mentors Wynn.

Peterson autographed the jersey, wishing Wynn, "Merry Christmas."

"I started to tear up," Wright said. "I know a lot of the athletes, and that moment made me feel like a kid again. Never had a player of that caliber, at a time when he was injured and worried that he may never play again, think of doing something so generous."

Peterson keeps giving, in so many ways.

Refusing to accept the logical and conservative timetables that would have had him easing his way into the season following his knee surgery, Peterson has rushed 96 times for 420 yards in five games. "I have the drive to be the best ever to play," he said Thursday. "I couldn't just go through the motions. I had a fire burning in me."

Ten months after an injury that may have slowed a lesser athlete, Peterson is eying another decade in the league, noting that a certain Redskins linebacker has lasted. "London Fletcher is 37," Peterson said. "I'm 27. That's 10 more years. I feel like I can go for a long time. There's a lot you can do with your body when you're well-conditioned. Herschel Walker, today, I'm sure he's benching over 400 pounds and they say he just ran a 4.4 or 4.3 40."

Buoyed by his team's 4-1 start and Percy Harvin's transformation from versatile oddity to star, Peterson calls himself and Harvin the two best players in the league. "I know talent," he said. "I can watch Michael Jordan and Scottie Pippen and see the difference."

Who's Pippen and who's Jordan? "There are two Jordans on this team," he said. "I'm not trying to be cocky. I'm just very confident in my abilities."

And Harvin's. He remembered watching the national championship game in January 2009, when Harvin played with a hairline fracture in his ankle yet looked like the best player on the field as his Florida Gators beat Oklahoma. "I watched that game, and I knew he was a star," Peterson said. "When he came out in the draft, I knew there was a chance for him to drop to us."

The Vikings once landed Randy Moss with the 21st pick in the 1998 draft. Because of injury concerns, Peterson fell to them at No. 7 in 2007. They landed Harvin with the 22nd pick in 2009.

"The way they evaluate talent here, I knew we wouldn't pass on him," Peterson said. "They didn't pass on me. Those three names right there -- c'mon, how are those guys not taken in the top five?

"Percy is the best player I've ever played with."

Peterson's return to FedEx Field is one of the prominent NFL story lines this week. He shrugs off the memories as if they were arm tackles. "I was in disbelief," he said. "But by the time we took the flight back, I was thinking about rehabbing it. I turned the page."

But not before leaving a Christmas present for someone he had never met.

"That was a life-changing experience for Keenan," Wright said. "He has Mr. Peterson's jersey hanging now. He's doing better in school and he's excellent in sports.

"When Keenan wanted to meet Adrian, I told him, 'If you believe in something bad enough, it will happen.' Mr. Peterson made it happen."

Jim Souhan can be heard Sundays from 10 a.m. to noon and weekdays at 2 p.m. on 1500-AM. His Twitter name is SouhanStrib. jsouhan@startribune.com