From early on in 2007 through Week 1 of 2014, with the exception of a handful of games missed because of injury, you never had to ask what the Vikings' plan was at running back. It started with Adrian Peterson, and that was as close to 100 percent of the answer as any team could hope. Sure, he had backups and the Vikings employed third down/blocking backs, but Peterson was the man. There was no running back by committee, unless one man can be a committee.

The Cleveland Browns have had no such luxury since 2007. Since that season and including this one, six different players have lead the team in rushing: Jamal Lewis, Jerome Harrison, Peyton Hillis, Trent Richardson, Willis McGahee and Terrance West.

West is the last name on the list and is fewer than 100 yards ahead of Ben Tate, who was signed to perhaps be the team's feature back this season. Tate, of course, was released this week and picked up by the Vikings, who are almost certainly now going to be without Peterson for the rest of 2014.

Beyond that, the Vikings might be moving into a new era where they treat running backs like the Browns, Patriots, Broncos and so many other teams do these days: cycling through a bunch of them in the course of seasons and employing a committee approach during games. Peterson will be 30 before his NFL-imposed suspension is lifted, and as freakish an athlete as he is, NFL running backs have expiration dates and Peterson's contract makes it very convenient (and prudent) to cut him or trade him before the 2015 season. Peterson's off-field problems, in fact, could strangely make it easier in a way for the Vikings to sever ties without having it be purely a football or business decision.

But as encouraging as Jerick McKinnon's rookie season has been at times, he is not Peterson. No one person is going to replace Peterson, and perhaps no one person should. Because as nice as it was for the Vikings to pencil him in for 20-25 carries a game for as long as they did, and for Peterson to deliver in the way that he did, today's NFL does not demand a dominant running back. It demands an effective running game and an efficient, playmaking passing game.

There was only one Peterson, a gifted athlete who willed the Vikings to the playoffs in 2012 with a breathtaking season. There will always be a guy like Tate — with six career 100-yard games and two seasons over 750 yards to his credit — to grab in free agency or off the waiver wire to bolster a committee.

One is a convenient luxury (Peterson alone rushed for 4.5 yards per carry last season). One is an effective reality (the Vikings, primarily without Peterson this year, have averaged 4.6 yards per rushing attempt this year).

Now the Vikings are on the other side and might stay there for a long time.