Adrian Peterson is a running back who is so accomplished he probably winds up in the Pro Football Hall of Fame. He's also a free agent, able to sign with the team of his choice and reportedly willing to work for $5 million this season.

So why can't he find a home?

Answer: Leonard Fournette. And Dalvin Cook. And Christian McCaffrey. And Alvin Kamara. Basically, any top running back in this month's NFL draft. They have the young legs that Adrian Peterson does not -- and look no farther when wondering why nobody is in a hurry to sign the NFL's 16th all-time rushing leader.

I know the guy came this close to breaking Eric Dickerson's single-season rushing record of 2,105 yards, was a league MVP and led the league in rushing two years ago with 1,485 yards. But that's the point. It was two years ago.

Peterson was 30 then. He's 32 now. There's a world of difference between the two.

Take a look at the league's top-10 career rushers. After turning 32, not one of them averaged more than 4.0 yards a carry or led the league in rushing. Worse, the group combined ... combined ... for three 1,000-yard seasons, with one of them belonging to Emmitt Smith -- the NFL's career rushing leader.

He had 1,021 at the age of 32. He also averaged 3.66 yards a carry after his 32nd birthday.

Curtis Martin, the league's fourth all-time leading rusher, led the NFL with 1,697 yards when he was 31. A year later, he was hurt and produced 735, averaged 3.3 yards a carry and called it a career. The latest Hall-of-Fame running back, 2017 inductee LaDainian Tomlinson, ran for 280 yards and one touchdown when he was 32. Then he retired.

Now look at Peterson. He's coming off a season where he spent most of the year on the sidelines with a knee injury. But when he played, he did next to nothing -- running for 72 yards in three games and averaging 1.9 yards per carry. Granted, Minnesota's offensive line was about as effective as a Mideast peace treaty, but that's not the point.

This is: The number that scares off potential Peterson suitors is not the $5 million. It's the 32 years. Adrian Peterson is a descending player who is nearing the finish line and coming off knee surgery.

So whom would you trust? A young back with his career in front of him, or a future Hall-of-Famer who is 32 and missed all but four games in two of his last three years? I think you know the answer.

A year ago, the Dallas Cowboys' Ezekiel Elliott led the NFL in rushing. He was a rookie. Chicago's Jordan Howard was second. He was a rookie, too. And Miami's Jay Ajayi was fourth. He was in his second season and his first with more than 49 carries.

Three of the league's top four backs were no more than 23 years old -- and two of those guys took teams that missed the playoffs in 2015 into January one year later. NFL clubs looking for their next back don't need a GPS to find him, and neither do you.

Just attend next week's NFL draft.

It's wiser ... much wiser ... to invest in someone with young legs than it is someone with battered ones. Adrian Peterson can ... and maybe will ... help another club, but not as a full-time back. That role belongs to someone with a glittering future, not a star-studded past.

Elliott was the fourth pick of the NFL draft and cost the Cowboys $25 million over four years -- an average of just over $6 million per. Howard was a fifth-round choice who signed a four-year, $2.88 million deal -- an average of $720,000 a season. And Ajayi? He cost the Dolphins $2.5 million over four seasons, an average of $625,000 per.

Now we come to Adrian Peterson. He was the most decorated player on the Minnesota roster, yet the Vikings let him go because of the cost/reward factor. At 32, he simply wasn't worth the millions he was due to make. So the Vikings let him walk.

Now, others are letting him sit for the same reason.

"Youth has no age," Pablo Picasso once said. Unfortunately, NFL running backs do. And Adrian Peterson is on the wrong end.