INDIANAPOLIS – Eight years ago, Rick Spielman and the Vikings touched down in Indianapolis for the NFL scouting combine and flew home even more mesmerized by a bull of a running back whose eye-popping performance in spandex was even more impressive considering he was still recovering from a broken collarbone.

Fortune would soon be on Spielman's side in his first draft as vice president of player personnel when Oklahoma star Adrian Peterson, Spielman's second-favorite prospect behind freak Georgia Tech wide receiver Calvin Johnson, somehow was still on the board when the Vikings were on the clock for the seventh pick.

The rest is history. Six Pro Bowls, three All-Pro nods and one shiny MVP trophy later, Peterson proved to be the most productive running back of his generation.

His story, far from over by Peterson's estimation, has taken an ugly and unexpected twist, though, leaving no certainty that the final chapters will play out in Minnesota.

So there Spielman was Saturday, sitting in the stands at Lucas Oil Stadium as this year's crop of running backs dashed 40 yards and zigzagged around orange cones. The Vikings prefer Peterson remain in purple, but they are preparing to find his replacement in this year's draft should the need arise.

"Our philosophy is — and you've seen it through the playoffs — you have to have a quarterback, but you also have to be able to run the ball, especially if you're going to be playing in an outdoor climate," Spielman, now the team's general manager, said. "We value running backs pretty significantly."

Wisconsin’s Melvin Gordon is considered to be one of the few running backs with first-round potential.

One way or another, we will soon see just how significantly they value the position.

The Peterson problem

Mostly mum during the season as Peterson was on the commissioner's exempt list and then serving a suspension for hitting his 4-year-old son with a switch last May, the Vikings started shouting from the mountaintop last month that they want him to return to their team should he be reinstated from his NFL suspension April 15.

Spielman nudged the company line a little further Wednesday when he said that he expected Peterson to play — and run angry — for the Vikings this season.

"What team wouldn't want to have an Adrian Peterson talent?" Spielman said. "He's a unique player that you don't see come around too often. Adrian's been a key part of our organization. He's made a mistake. He's doing everything. And he's gotta follow through rectifying and doing everything the NFL is requiring him to do. Yeah, we expect Adrian Peterson to be a part of our football team."

The sudden show of widespread support from four top decisionmakers, none more significant than owner and team president Mark Wilf, was curious. Now we know why the Vikings, who are limited in their communications with Peterson as he serves his suspension, were purposely showing him so much love through the media.

On Thursday night, Peterson told ESPN that he was "uneasy" about the prospect of returning to the Vikings. He felt "ambushed" by the team's decision to work with the NFL to put him on the commissioner's exempt list in September.

He even expressed disappointment with how fans treated him in the wake of his child-abuse charge.

There is a chance this could be posturing on Peterson's part. He has a $12.75 million salary and a $15.4 million cap hit, highest at his position. With Peterson hitting 30 ­­— an age when few backs are still productive — in March, the Vikings are expected to approach him about redoing his deal if he is reinstated on or after April 15. By then, most of the NFL's free agent money will have been spent, giving the Vikings even more leverage when it comes to pressuring Peterson into a pay cut.

His comments could be his way of telling them not to bother asking.

Or maybe Peterson, who has not responded to requests for comment from the Star Tribune, really is ready to move on from the Vikings, maybe to a Super Bowl contender or a team in his home state of Texas.

This saga is far from over, but the Vikings are putting a plan in place in case they are without Peterson's services in 2015.

'The runner does matter'

The Vikings weren't the only team over the past few days expressing love for a running back.

Seattle General Manager John Schneider called Marshawn Lynch "a heartbeat guy" for a Seahawks team that rode the workhorse running back to the past two Super Bowls.

Dallas coach Jason Garrett scoffed when a reporter asked him about "plugging in" another running back behind one of the league's best offensive lines if the Cowboys lose DeMarco Murray, the league's leading rusher, in free agency.

"The runner does matter," Garrett said. "I think we've all seen that running backs don't seem to be drafted quite as high as they used to. I think that has a lot to do with the longevity of the player. But I do think the value of the running back is really, really critical to having a great running football team. I think the history in the NFL proves that. Recent history proves that."

Actually, many numbers support the notion that the position has become devalued in today's pass-happy NFL. Like the 50 passes that New England's Tom Brady threw to beat the league's top defense in the Super Bowl. Or the fact that no free agent back has signed for $5 million or more a season since 2008. Or the lack of first-round running backs drafted since 2012.

Ending the drought?

During each draft from 1964 to 2012, at least one running back was selected in the first round. In each of the past two drafts, though, none was taken until the second.

That 2012 class is a good case study on the perils of investing a high pick on a position that has the NFL's shortest shelf life.

Trent Richardson, selected third overall by Cleveland, has been a bust for two teams. Doug Martin had a strong rookie year for Tampa Bay, but injuries have limited his production. A neck injury forced David Wilson, another first-rounder, to retire. The most productive runner has been Alfred Morris, a sixth-round pick of Washington.

It might be a long time until we see an NFL team spend a top-10 pick on a running back again like the Vikings did with Peterson, but the first-round drought could end in April.

"I think there is that possibility this year," Arizona coach Bruce Arians said. "You might see two."

Georgia junior Todd Gurley is 6-1, 222 pounds and an explosive athlete. He rushed for 911 yards and nine touchdowns before a torn ACL ended his season in November. He was unable to run at the combine and reportedly didn't let NFL team doctors check his knee out in Indianapolis, so there is plenty of risk there. But the potential reward with him may be higher.

"I'm definitely not Adrian Peterson," Gurley said when asked about working his way back from his knee injury. "I mean, that guy is a freak of nature. But my goal is to be a freak of nature as well and try to get back as fast as possible. But I'm not going to rush anything."

Vying with Gurley to be the first back off the board is Wisconsin junior Melvin Gordon. He rushed for 2,587 yards in 2014, coming up 41 yards short of Barry Sanders' single-season NCAA rushing record. The 6-1, 215-pound Badgers star also scored 29 rushing touchdowns, most in the country.

Gordon predicted that at least one running back in this class — himself perhaps — will "show people that we're capable of going in the first round."

'A pretty strong group'

Spielman, who raved about the depth and talent in this class, agrees that there are running backs worthy of a first-round pick.

"I don't know what other teams are thinking or what their philosophies are," Spielman said. "But I know there's some running backs in this draft, at least in my opinion, that have that type of talent."

The Vikings don't plan on paying for a running back in free agency, and they should know where they stand with Peterson by the start of the draft April 30. But even if they can settle their differences with him, they might still target a running back outside of the first round to complement Peterson and second-year scatback Jerick McKinnon.

Draft analysts say there are several prospects capable of carrying the load, and the consensus among general managers is that this is the best class in a while.

"The running back group has been enhanced with the inclusion of the underclassmen," Pittsburgh general manager Kevin Colbert said. "It's actually a pretty strong group."

There are elusive runners such as Nebraska's Ameer Abdullah and Miami's Duke Johnson. Bruisers such as Alabama's T.J. Yeldon and the Gophers' David Cobb, who injured himself running the 40 during the combine and whose status is yet unknown. Speedsters such as Indiana's Tevin Coleman and Michigan State's Jeremy Langford. And USC's Buck Allen and Boise State's Jay Ajayi were complete college backs with little fanfare.

The Vikings surely will leave Indianapolis even more impressed with a few of these young running backs. But there is only one Adrian Peterson.

"You understand that if you get him back he's a different, special guy," coach Mike Zimmer said. "Not all guys can run like Adrian can."

The Vikings would prefer that he is back to being the focal point of their offense in 2015. But they are also preparing as if that generational talent, the one who blew them away at the 2007 scouting combine, will be penning the final chapters of his career elsewhere.

Matt Vensel • matt.vensel@startribune.com