New head coach Mike Zimmer has trumpeted that competition will reign supreme during his first Vikings training camp. But if any starter has already been etched into stone onto Zimmer's depth chart, it is Adrian Peterson at running back. That doesn't mean there is nothing to see here. A new coordinator and an interesting rookie should spice up the position this summer.

After looking at the quarterbacks yesterday, our next position breakdown is the running backs.

WHERE THINGS STAND: Back on the field after offseason groin surgery, Peterson was an active participant in Zimmer's first offseason program. And he spent a lot of that practice time snagging passes, something he hasn't been asked to do much of during his superlative Vikings career. New offensive coordinator Norv Turner in his past stops utilized running backs such as LaDainian Tomlinson and Darren Sproles in the passing game. Peterson has seemingly embraced the change in his role, saying that he doesn't mind sacrificing rushing yards if it helps the team (and also helps keep him fresh). Make no mistake, though, pounding the rock with Peterson is still going to be a focal points of the Vikings offense. Matt Asiata and Joe Banyard are competing with third-round pick Jerick McKinnon for carries behind Peterson, who turned 29 in March. Jerome Felton, a 2012 Pro Bowler, returns at fullback, but he could be pushed by 24-year-old Zach Line.

CAMP BATTLE TO WATCH: While Peterson has the top tailback spot locked up, there is an opportunity for others to get on the field on third down. The Vikings drafted McKinnon in the hopes that he could become their third-down running back. He didn't catch many passes in Georgia Southern's triple-option offense, but he looked comfortable running routes and making catches during offseason workouts. Pass protection will be important, though, and McKinnon admittedly has a lot of learning to do in that area because of the offense he played in during college. Meanwhile, Zimmer and Vikings like Asiata's versatility and reliability, so he will be in the mix, as well. And don't rule out Peterson hogging a big chunk of the third-down snaps, too.

THE BURNING QUESTION: How are the Vikings going to use McKinnon? We got a glimpse during offseason workouts and the minicamp, but we will get a better idea during training camp. McKinnon is quick, shifty and one of the most athletic players on the roster. To put his skill set to use, though, they will have to take Peterson off the field -- or find creative ways to use them together. Could a Sproles-type hybrid role be in the plans for the rookie? We'll soon find out.