We've crunched the numbers and come up with 570 reasons the Vikings will take a running back as high as the third round in next month's NFL draft.

The first 538 represent the league-high discrepancy between Adrian Peterson's carries and the next-highest total by a Viking the past two years. To get a sense for just how huge that is, consider that No. 2 on the list is now-former Tennessee Titan Chris Johnson at 437. Only one other NFL back has a discrepancy higher than 383.

The next 29 reasons represent Peterson's age. It's hard to put Peterson in a statistical box when he's already gone superhuman and run for 2,097 yards just one season after knee reconstruction. But raise your hand if you're comfortable with Matt Asiata, a former undrafted fullback with 47 career carries, standing between Peterson and considerable data that support the obvious argument that most running backs peak at 27 and do not go gentle into that good night.

And the final three reasons represent the streak of consecutive offseason surgeries that Peterson is riding. Knee, hernia, groin is not a favorable trifecta.

The person who hatched this crazy notion that the Vikings will draft a running back fairly high asked Peterson if he's ever wondered how long he can play at his level and whether sharing carries more evenly would be beneficial.

"Not at all, man," Peterson said.

When Peterson joined the NFL in 2007, he spent a lot of time asking older veterans how they became, well, older veterans. Fullback Tony Richardson and left guard Steve Hutchinson had two of the brains that Peterson picked. They told him to take care of his body ASAP and never stop.

"Even Favre," Peterson said. "Brett wasn't a guy who got in the cold tub and iced his legs and did foam rollers [to loosen muscles] and things like that. But that's one thing I learned is you've got to take care of your body."

No one in the league does that with more intensity, duration and attention to recovery and diet than Peterson. But that doesn't mean it isn't time for his team to make another meaningful investment at his position.

Since Peterson was selected seventh overall in 2007, the Vikings have drafted one running back. That running back was Toby Gerhart, a second-round pick in 2010. Gerhart signed with the Jacksonville Jaguars this offseason.

Rick Spielman has orchestrated the Vikings' drafts since 2007 and has had final say since being promoted to general manager in 2012. He led the charge that selected Peterson three months after Chester Taylor concluded a 1,216-yard season in 2006. And he was directing the war-room traffic when the Vikings picked Gerhart 51st overall to replace Taylor when he left in free agency.

In other words, ESPN draft guru Mel Kiper Jr. might be spot on by projecting Auburn running back Tre Mason to the Vikings with the third-round pick (96th overall) that they received as part of the Percy Harvin trade.

Peterson's greatness and unprecedented ability to rebound from major injuries reduced Gerhart to spectator throughout most of his rookie contract. Now, Peterson makes it sound like he's determined to do the same thing again should the Vikings draft another running back.

"I look on YouTube all the time," Peterson said. "I see guys 40, 50 years old running 48 [seconds] in the 400 [meters] and 4.3s in the 40 [yards]. It's all because they put the work in. As long as you have the mind-set to work and you have what you need to take care of the body, then you're able to extend your ability."

Nothing would make the Vikings happier, but there's comfort in having good insurance. It's also time to consider a less-is-more philosophy with Peterson's carries, not to mention taking a firmer stand against him when he wants to play through significant injuries.

Of course, without Gerhart, the best way to accomplish all of this is to make another strong draft-day investment at running back.

Mark Craig mark.craig@startribune.com