[Note From Adam:  This is part two of my position-by-position breakdown of this Vikings roster.  Part one, The Passers, can be found by clicking here.]

The Vikings running game was not unsuccessful in 2011, as they ranked fourth in the league, despite numerous challenges such as struggles along the offensive line and injuries to their running backs.  The position of running back, however, suddenly has a number of question marks that need to be discussed this offseason.

Let’s take a closer look.

LAST SEASON

For the first time in his five year career, Adrian Peterson did not top 1,000 yards during the season.  This is mainly due to an ankle injury that caused him to miss three games, and then a devastating ACL and MCL injury that ended his season in week 16.

Peterson ended up rushing for 970 yards in the 12 games he did appear in, a 4.7 yard per carry average, and scored 12 rushing touchdowns.  In week eight against the Panthers, Peterson flashed his potential as a pass catching back posting a career best five catches for 76 yards and a touchdown, with rookie Christian Ponder at the helm.

When healthy Peterson showed no signs of slowing down his production as a power back, looked like he possibly improved as a pass catcher, and continued good ball security for his second season in a row.  The knee injury, and his current rehabilitation efforts and timeline, is currently the biggest question facing Peterson’s outlook for 2012.

Backup Toby Gerhart saw an increased role in Bill Musgrave’s offense this season and improved the numbers posted in his rookie season.  Gerhart played in all sixteen games, starting five, rushing for 531 yards on a 4.9 yard per carry average, scoring one touchdown.  He also caught 23 passes for 190 yards, and improved on his fumbles with only one on the season.

Gerhart suffered an MCL injury in the final week of the season, but no surgery is needed, and he projects as Adrian Peterson’s primary replacement if it comes to that at the beginning of 2012.

For all practical purposes, Percy Harvin was the Vikings third running back option in 2011, with a career high 52 carries.  Harvin posted a 6.6 yard per carry average for a total of 345 yards and two touchdowns.  Combined with his receiving duties, Harvin fumbled the ball twice, losing both.  He stands to continue being used in this versatile role, getting a good dose of carries in 2012.

The fourth option the Vikings turned to was Lorenzo Booker who carried the ball 13 times for 52 yards and had eight receptions for 82 yards.  Anyone who touches the ball so seldom but still manages to fumble the ball three times is almost certain to be on his way out the door.

Fullback Ryan D’Imperio, whose experience as a college linebacker makes versatility and contributions on special teams his most attractive attribute, never carried the ball once in 12 appearances.  He did post two catches for seven yards, and was an inconsistently decent blocker when called upon to do so.

Athletic quarterbacks Christian Ponder and Joe Webb bolstered the Vikings rushing totals by combining for 373 yards, and Webb scored twice with the ball in his hands.

CURRENT ROSTER

General Manager Rick Spielman has already stated the obvious this offseason:  Adrian Peterson is not going anywhere.

There is good reason for that.  Prior to 2011 Adrian Peterson signed a blockbuster deal worth up to $96 million over seven years.  $32 million of that is guaranteed for skill, while $4 million is guaranteed for injury.  His 2012 base salary is reported to be $8 million.

Toby Gerhart is entering the third year of the four year deal he signed as a rookie.  He is expected to get paid $490,000 as a base salary for 2012.  Gerhart is highly unlikely to be going anywhere.

Lorenzo Booker is a restricted free agent this offseason, but it appears that his lack of production, proneness to fumbles, and Rick Spielman’s desire to get younger could lead the Vikings to pass on the opportunity to tender him and retain his services.

Ryan D’Imperio’s contract has not been disclosed, but it is not expected that he will be a free agent this offseason.  Jim Kleinsasser, 2011’s primary lead blocker, has announced his retirement.  Fullback Matt Asiata was signed to a futures contract after the season and is likely to get another chance to earn a roster spot during training camp.

Undrafted rookie Caleb King has two years left on his contract with the Vikings, as does Jordan Todman who the Vikings swiped off the Chargers practice squad near the end of the season.  Both have an uphill battle to make the roster, but Adrian Peterson’s injury and Lorenzo Booker’s likely departure could give them a chance to duke it out with each other in training camp.

FREE AGENCY

Matt Forte, Arian Foster (restricted), Marshawn Lynch, and Ray Rice are going to be the best free agent running backs available if any of them manage to make it to the open market.

The Vikings will not be interested in any top tier running backs during this free agency period, however, as they already have so much invested into Peterson and Gerhart.  If the team adds anyone in free agency, it will be someone that is viewed as financially expendable when Peterson returns to the field.

If the Vikings are missing a dimension in their backfield, it is that of a true scat back type of player, a concept that I have been preaching for years.  Heck, the Saints managed to make their offense even more potent than it already was by adding Darren Sproles to the mix.

Guy like Tashard Choice or Jerious Norwood might be able to fill that role on the cheap, but I highly doubt the Vikings invest even that much into the position.  If Peterson’s rehab seems to look more and more like an in-season venture, the Vikings may also consider signing veterans still available in the summer like possibly LaDanian Tomlinson, Mewelde Moore, Ronnie Brown, or even Chester Taylor.

If the Vikings are going to invest any serious money into the running back position it should be to secure the services of a true fullback.  Bill Musgrave has expressed in the past that his offense does not necessarily need a fullback, however, so the scenario of the Vikings signing a big name to fill this position seems unlikely.

The best fullbacks that will possibly be available in March are Le’Ron McClain, Earnest Graham, and Jacob Hester.

DRAFT PROSPECTS

With so many pressing needs on their roster, the Vikings are yet again unlikely to invest much into the running back position once the Draft rolls around.  If they do select a running back, it will probably be due to a very solid value falling to them in the later rounds.

While the Trent Richardsons and Lamar Millers of the world will be the big names selected near the top of the Draft, the Vikings will have no interest in using one of their top picks on these guys.

Instead, watch for them to eyeball versatile scat backs with special team’s value such as Chris Rainey (Florida) or Ronnie Hillman (San Diego State) near the end of the Draft, or as possible undrafted free agents.  If the Vikings do nab another back, it will be to add them to the mix as competition for Caleb King and Jordan Todman.

Guys like Drake Dunsmore (Northwestern) or Cody Johnson (Texas) could present the Vikings with a big enough upgrade to the fullback position to warrant a selection at the end of the Draft, as well.

OTHER POSSIBILITIES

If the Vikings wanted to cause real ruckus, they could make a play that would greatly upgrade their fullback position by trying to sign away a top tier restricted free agent fullback.  Pay attention to what levels the Raiders tender Marcel Reese and the Cowboys tender Tony Fiammetta.

If those two teams try to be cheap and offer very low tenders, I will immediately jump on the “sign ‘em away” bandwagon.  Of course, me being on that bandwagon will have zero effect on Rick Spielman’s thought process.

PROJECTIONS

First off, Peterson and Gerhart will be on this team, and I also believe Booker will not be.

Watch for the Vikings to continue to reshuffle the bottom of their depth chart with some more minor moves involving late draft picks, uber-cheap free agents, or undrafted rookies.

In the end, I think Caleb King and Jordan Todman will be battling for the third spot on the roster at tailback, meanwhile Ryan D’Imperio and Matt Asiata will be doing the same at fullback.

No major changes on the horizon at tailback, and a minimal chance of turnover at fullback unless a major steal falls in the team’s lap on Draft Day.