It took the Saints just four games to know that 32-year-old Adrian Peterson wasn't going to work out. So they sent him to Arizona where the running back is still looking to recapture the form that made him one of the league's best players from 2007-2015.

And while New Orleans may have given up on Peterson -- Saints coach Sean Payton called the decision to trade Peterson "common sense" -- the Cardinals' newest running back insists he can play another four or five seasons.

"I have so much left," Peterson said Wednesday, via AZCardinals.com's Darren Urban. "I have a lot left in the tank. Stay tuned, and you'll be able to see it first-hand."

Perhaps Peterson should first worry about getting right in 2017. In four games with the Saints, he totaled 27 carries for 81 yards and no touchdowns. His longest carry went for 11 yards and he never averaged more than 3.7 yards per carry in any game. And this is after he played in just three games last season because of injury, and managed 1.9 yards per carry. Juxtapose that with his career average of 4.8 yards per carry and it's easy to understand why the Saints were happy to ship Peterson out west for a conditional draft pick.

Last June, some two months after the Saints signed Peterson to a two-year deal, his new teammates marveled at how impressive Peterson looked during offseason workouts.

"He's a stud, man. He looks the part," Saints quarterback Drew Brees said at the time. "There's something about handing the ball off to that guy and watching him run through the hole and take on anybody who tries to tackle him."

Saints left tackle Terron Armstead added: "I'm amazed, honestly. Seeing him just take off his first few steps are as explosive as I've ever seen by a human being. It's unbelievable. I'm very excited to see him when the pads come on."

And here's Saints safety Kenny Vaccaro: "It's ridiculous. He has not lost any steps. Wait, just watch. He's so explosive ... just in flat shoes out there."

Unfortunately, everything changed once Peterson donned pads. This shouldn't be a surprise since, as we wrote over the summer, a feature back's existence, in general, burns brightly before flaming out. And while it's not uncommon for a 32-year-old running back to have a good season, the reality is that it would be more likely that Peterson will be just a shell of himself. There is no shame in that because unless you're a franchise quarterback, professional football is a young man's game.

It's just not clear if Peterson knows this yet.