On Friday, the future of the Vikings backfield was running the rock at Winter Park.

Or was he down in Houston, working out like a madman despite being suspended?

Or was that him in Athens or Madison or Lincoln or some other college town? More than one answer will probably end up being correct. But which?

The Vikings, after drafting Adrian Peterson seventh overall in 2007, haven't had to give much thought to the running back position, other than determining who would get the four or five carries a game when Peterson needed a breather.

But things will be different this offseason, as they figure out what to do with an aging and highly paid star turned social pariah.

The landscape has shifted since the Vikings first pounded the ground with Peterson seven years ago, and things have even changed significantly since they gave him a six-year, $96 million ­extension just three years ago. The majority of NFL teams are going with a committee approach at the running back position, and the Vikings seem poised to join them in the near future.

"In general, most teams are going to have two backs because of the pounding the backs take in this league," GM Rick Spielman said earlier this month. "Especially, if you're going to run the ball, you're going to need two backs who can come in and stay fresher throughout the season."

But next season, will Peterson still be one of them? Where do rookie Jerick McKinnon and the newly acquired Ben Tate factor in? And will the Vikings draft another running back this spring, perhaps one with an early pick?

The Peterson question must be answered before the others.

Money issues ahead

Peterson's future in Minnesota beyond 2014 was already in doubt before he was charged with injury to a child in Texas in May, pleaded no contest to a misdemeanor of reckless assault earlier this month and was suspended for the rest of the season by the NFL on Tuesday.

In the NFL, it almost always comes back to money. And no team has more money tied up in a running back than the Vikings, who allocated 11.2 percent of their salary cap spending to Peterson this season. He is the only NFL running back with an eight-figure cap number.

Peterson, under contract through the 2017 season, will carry a cap number of $15.4 million in 2015. It balloons to $17 million by the final year of the deal.

Joel Corry, a former sports agent who writes about the business of football for CBS Sports, said that even before Peterson's legal problems he was skeptical about Peterson's chances of playing for the Vikings in 2015.

"His contract doesn't bear any relation to the rest of the running back market. I know Peterson had some unique value as the face of the franchise with the new stadium opening in 2016, but that doesn't exist anymore," Corry said. "From a pure economic perspective, having a 30-year-old running back in 2015 with a $15.4 million cap number and $13 million salary wasn't going to be the most efficient use of resources."

The Vikings will likely approach Peterson about restructuring his deal. But a proud man and still a productive runner when we saw him last, he might not be receptive.

Further clouding his future in Minnesota were his comments in an interview with USA Today, including Peterson saying he has given thought to the idea that "maybe it's best for me to get a fresh start somewhere else."

"I would love to go back and play in Minnesota to get a feel and just see if my family still feels comfortable there," Peterson said in the interview. "But if there's word out that hey, they might release me, then so be it. I would feel good knowing that I've given everything I had in me."

And with 2,054 regular-season carries before his 30th birthday, it's fair to wonder how much Peterson — a freak athletic specimen but a mere mortal still — has left to give a team.

A devalued position

In 2012, when Peterson nearly ran down the NFL's single-season rushing record, the Vikings pushed his limits with 348 carries; 86.8 percent of the team's running back carries went to Peterson.

Few backs today have been durable and productive enough to warrant that kind of workload.

With running back having the shortest shelf life of NFL position groups, according to NFLPA data, and with the league's biggest contracts being handed out to quarterbacks and wide receivers (and also the pass rushers and cornerbacks who must contend with them), teams are spending less money on marquee backs and going with more of a committee approach.

Six NFL teams have given one lead runner more than 75 percent of their running back carries this season. Nine teams, meanwhile, have at least two backs with 75 or more carries apiece — the Vikings are one of them — and 22 teams have at least two with 50 or more.

Dallas' DeMarco Murray leads the league with 1,233 rushing yards on a whopping 244 carries, but that heavy workload will be a cause for concern for potential employers and will likely cost him when he hits free agency next March.

Free agency, after all, has not been kind to running backs in recent years.

Chris Johnson got the highest annual salary, including bonuses, this past offseason when the New York Jets gave him $8 million over two years. Former Vikings back Toby Gerhart got $10.5 million over three years from the Jacksonville Jaguars. Tate got $7 million over two years from the Cleveland Browns, who waived him on Tuesday.

And all three of them have proved not to be worth even those modest deals.

"Running backs have been devalued," Corry said. "It's been a buyer's market in free agency in recent years with running backs."

College no proving ground

Teams aren't spending much draft capital on running backs, either.

No running back has been selected in the first round of the NFL draft since 2012, when Trent Richardson, Doug Martin and David Wilson went in the first 32 picks. Richardson has already been traded, Martin has been a regular on the injury report, and a neck injury forced Wilson to retire after 21 games and 115 carries.

This past May, 53 players were drafted before the first running back, Bishop Sankey, who is in a committee for the Tennessee Titans. McKinnon was the seventh back off the board 42 picks later. A few backs drafted after him have earned starts this season or gotten them because of an injury.

Of the league's top 10 rushers, one (Alfred Morris) was a former sixth-round pick and another (Justin Forsett) went in the seventh round. Arian Foster wasn't even drafted in 2009.

Neither was Jonas Gray, who rushed for 201 yards and four touchdowns last Sunday night.

Tate lost his job in Cleveland to a 2014 third-round pick and a rookie who went undrafted.

"The more you talk to folks around the NFL, it's becoming obvious that the data — call it 'Moneyball' if you want — tells teams that they can win by investing in running backs outside of the first round and even outside of the top 100 picks," said Matt Miller, an NFL draft analyst for Bleacher Report. "With quarterback salaries constantly climbing, the money has to come off the salary cap somewhere, and running back is becoming one of those areas where teams can win cheaper."

Miller said that Georgia's Todd Gurley was poised to be the now-rare first-round running back next spring. But a torn ACL has put his future at Georgia and his draft position both in doubt.

Miller feels that Wisconsin's Melvin Gordon, Nebraska's Ameer Abdullah, Indiana's Tevin Coleman and Miami's Duke Johnson are "all special backs in their own right." But if the Vikings want to draft one to pair with McKinnon, they can probably wait until Day 2 to do so.

"Gurley was the rare talent that NFL teams are willing to invest a first-round-pick in," Miller said. "Now it looks like a deep draft at running back, but a lot of Round 2 players and no Round 1 star."

Trial by fire

These final six games will give the running backs on the roster — specifically McKinnon but perhaps Tate, as well — an opportunity to show the Vikings that they don't need to prioritize their position in the offseason.

The Vikings brought in Tate in large part because of injuries to McKinnon and Matt Asiata this week. But the next month and a half will serve as an extended tryout for Tate, whom the Vikings can cut after the season with no future cost.

More important, though, the Vikings must get a clearer picture of what they have in McKinnon, who despite facing a steeper learning curve than most rookie running backs surprisingly ranks 18th in the NFL with 484 rushing yards on 4.9 yards per attempt.

McKinnon was perhaps the most athletic back in the 2014 draft, testing among the top performers at pretty much every combine event. But he played his college ball at small-school Georgia Southern, who used him mostly as a quarterback in their triple-option running offense, which attacked defenses laterally instead of with a pro-friendly downhill run game.

McKinnon has had to learn to be patient while waiting for vertical running lanes to open in the pros — and his pass protection remains a work in progress — but he has impressed the Vikings with his vision, quickness and elusiveness. He has flashed receiving skills, too. And the 5-9, 208-pound rookie has surprisingly packed a little punch when running between the tackles.

"I think we're excited about Jerick and what he's done, and I see him as our running back," offensive coordinator Norv Turner said this past week.

McKinnon, who was expected to be a pass-catching back and a change of pace to Peterson this season, has been getting an on-field education that no one expected him to get this quickly. This starting experience has him convinced that he can be the No. 1 back if Peterson isn't on the team in 2015.

"I know I'm ready. I've been growing a lot this year," McKinnon said. "It is only going to make me better for next year. I'm ready. But whatever the organization decides — it's up to them — I'm just going to continue to go hard and contribute what I can."

The organization, of course, has a lot of decisions to make before next season. Should Peterson remain with the Vikings? Is Tate worth keeping? Will they need to bring in another runner in free agency or the draft to be their lead back?

It will be an unfamiliar experience for the Vikings, having to answer so many questions at a position that Peterson has dominated for nearly a decade.