MANKATO – Adrian Peterson took a handoff flowing to his left. Spotting a crease up the middle, he burst through his opening and jogged 15 yards alone before returning to the huddle.

It was one of Peterson's first carries in the first team drill of the first practice of training camp Sunday. He wore shorts, no full pads and wasn't allowed to be tackled.

That run meant nothing. And yet the moment felt strangely familiar, something he's done countless times in his career.

It represented a return to normalcy.

Peterson is officially back, happy and healthy after a long, painful ordeal, and now any conversation about him revolves mostly around football.

Thus, the key question has changed, too. No longer a matter of if Peterson will play for the Vikings again, the focus shifts to, how productive can he be for the Vikings?

That topic sparks a variety of opinions.

History has not been kind to running backs on the wrong side of 30. Only 46 times in league history has a running back in his 30s rushed for 1,000 yards.

Peterson turned 30 in March and is returning after essentially missing a full season. Those two factors — plus the wear and tear amassed from 2,147 career carries and a few injuries in recent years — have fueled chatter that Peterson won't be the same player he was pre-suspension.

That's a reasonable argument. Any scenario seems plausible. The belief here, though, is to never bet against Peterson's capabilities on the field because he's not just any running back and he has proved us dead wrong before.

Many of us assumed that his ACL surgery in 2011 would significantly alter his career arc. He wouldn't be the same player. The injury was career-threatening. His best days were behind him.

Those theories seemed reasonable at the time. Until Peterson put on his Superman cape and rushed for 2,097 yards the next season in becoming the league's Most Valuable Player.

It's a stretch to think he can duplicate something along those lines. He's older and has more miles on his tires. And his situation is different.

The Vikings don't need Peterson to play the role of superhero anymore. Their success depends as much on Teddy Bridgewater's guidance as it does Peterson's legs.

But Peterson remains capable of producing the kind of season that dispels any notion that he's huffing and puffing into the twilight of his career. Never discount his pride, or preparation.

"It would be a mistake to doubt him," veteran center John Sullivan warned. "We expect the same Adrian we've always seen. He'll be the most dynamic running back in the NFL."

Don't know if that statement ultimately will be proven true, but nothing about Peterson's appearance or demeanor suggests he's ready to turn into a pumpkin.

He seems to be in dynamite shape. He's still chiseled like a statue.

Could the year layoff result in some early-season rust? Sure, it's certainly possible. But Peterson hardly looks a guy who spent the year sitting on the couch and eating Doritos while catching up on soaps.

His motivation always has stemmed from his desire to be judged as the greatest all time at his position. And now a popular theory is that his motivation will exceed its normal capacity, if that's even possible.

We've all repeated the logic: Peterson will run angry and be extra motivated because of all the things he's heard about himself the past year.

Peterson already runs angry. He takes handoffs like a bull coming out of a chute. He never shortchanges himself or his team on the field.

Ordinarily, the "extra motivated" angle feels like an artificial attempt to create a narrative. And yet with Peterson, it becomes more believable because he's always viewed any criticism, setback or skepticism about his lofty goals as a personal challenge to prove something or someone wrong.

It's as if his antenna always detects that outside noise.

"A guy like Adrian," safety Harrison Smith said, "he's always at the top of motivation levels. But I'm sure he still wants to prove a point."

A longtime confidant of Peterson noted that his friend is in a good place mentally now. He's healthy, refreshed and seems excited to be playing football again.

Does that mean he has another highly productive season [or more] left in him? I wouldn't bet against it.

Chip Scoggins • chip.scoggins@startribune.com