Vikings training camp snapshot: Linebackers

Aaaaand …. here we go! In many ways, the Vikings' 2013 season officially gets underway Friday – first training camp walkthrough at 10:30 a.m., first practice at 2:45 in Mankato. And yes we know a lot can and will happen between now and Sept. 8, the day the Vikings open the regular season at Detroit. But taking the 90 players currently on the roster, we're delivering our in-depth position-by-position report as a primer for the opening of camp.

LINEBACKERS

Currently on roster: 10

Likely to make opening day roster: 6

Certain to make the team: Chad Greenway, Erin Henderson, Desmond Bishop, Gerald Hodges

On the bubble: Audie Cole, Marvin Mitchell, Larry Dean, Tyrone McKenzie

Practice squad candidates: Michael Mauti, Nathan Williams

What we'll be watching: Bishop and Henderson, first and foremost. Head coach Leslie Frazier announced on Thursday afternoon that Bishop would start camp as an outside linebacker with Henderson anchoring things in the middle. But we'll be interested to see if Bishop's progress in learning the defense and gaining confidence gets him at least a few reps in the middle. After missing all of last season with a severe hamstring injury, the former Packer will have to prove that his burst is back, that he's not tentative, that he can quickly get up to speed with a new team in a new defense.

Outside of the Henderson-Bishop subplot, Mauti's recovery from his third ACL tear is worth monitoring. The injury came last November, which means the rookie is nearing the end of his rehabilitation and could be cleared for practice right away.

Beyond that, the battle for roster spots among a solid group of linebackers will hinge heavily on special teams worth.

Star Tribune offseason excerpt:

Now begins the spring experiment of pushing Henderson inside from the weakside position he's started at the past two seasons. Henderson said he'll be the starting middle linebacker when the team's Organized Team Activities begin later this month. He's up to 249 pounds from his old playing weight of 240.

As for any internal apprehension that moving Henderson inside might further expose his bad habit of wandering out of position while trying to make the big play, the linebacker has his response, believing gap control was a bigger deal playing on the weakside, when chasing the action was more dangerous.

"It's not really the same kind of situation once you move over to that mike," Henderson said. "You still have to stay at home, still have to stick to your responsibilities. But I think they give you a little bit more freedom here at the mike to go find the ball and make plays."