Could the Vikings switch to a 3-4?

MINNEAPOLIS -- As the Minnesota Vikings comb through their list of coaching candidates -- which general manager Rick Spielman promised would be extensive -- they'll talk to some, like Arizona defensive coordinator Todd Bowles and Seattle defensive coordinator Dan Quinn, who might bring a 3-4 defense or a hybrid of the 3-4 and 4-3 to Minnesota.

The Vikings haven't employed a 3-4 defense as their base scheme since the 1980s, and even now, their personnel skews toward the 4-3 defense they've used for years. But if a coach did want to run the 3-4 in Minnesota, the Vikings might be at a point where they'd have enough flexibility to try it.

A switch like that would probably affect defensive ends Brian Robison and Everson Griffen more than anyone, but both could profile as outside linebackers in a 3-4 scheme. The Vikings toyed with Griffen as a linebacker during their 2012 training camp, and while Griffen has said he prefers to stay on the defensive line, the Vikings have dropped him into coverage at times, too. He was in pass coverage on 29 snaps this year, according to Pro Football Focus, which is more than any other Vikings defensive lineman, and Griffen's 29-yard interception return touchdown in 2012 came when he slipped into coverage, fooled Rams quarterback Sam Bradford and jumped in front of a pass. Griffen is a free agent after this season, but his size (6-foot-3) and speed (he ran a 4.66-second 40 coming out of college) could entice a 3-4 defensive coordinator.

The Vikings just gave Robison a four-year extension based on what he'd done as a defensive end, but he, too, could have the skill set to try a switch. He didn't sound opposed to the possibility when I asked him about it last month. "I'm open to whatever," he said. "I played linebacker in college. I'm open to a 3-4 scheme. I'm open to a 4-3 scheme, just whatever's going to help us win ballgames." Robison was a middle linebacker during his first year at Texas before switching to defensive end, but his profile isn't much different than Griffen's; he stands 6-foot-3, weighs 259 pounds and ran a 4.67 40 at the NFL scouting combine. If both players could adapt to playing in pass coverage, the Vikings might be able to use them in a 3-4. At the very least, if Quinn were going to run his hybrid scheme in Minnesota, Robison or Griffen could be the swing player who splits his time between the defensive line and linebacker.

When Quinn was the defensive coordinator at Florida, he coached Vikings tackle Sharrif Floyd, who was a five-technique end in Quinn's scheme. Floyd said after the Vikings drafted him that he'd played everywhere from nose tackle to defensive end in college, and while he'd probably stay as a three-technique tackle in a 4-3, he's got plenty of 3-4 experience. Linebacker Desmond Bishop, who tore his ACL in October, will be a free agent, but played his best football as a 3-4 inside linebacker in Green Bay.

And safeties Harrison Smith and Robert Blanton ended their college careers playing in a 3-4 for Brian Kelly at Notre Dame. Cornerback Xavier Rhodes was in a 4-3, but if the Vikings played a 3-4 style that allowed Rhodes to play man coverage and press, he might fit in better than he did in the team's old Cover-2 scheme.

If the Vikings were going to make a switch, they'd have to consider a handful of issues. First, they'd need to find a wide-bodied defensive lineman who could possibly occupy two defenders on the line of scrimmage, and they'd have to figure out where linebacker Chad Greenway fits, whether that's as an inside linebacker or possibly as an outside linebacker. They'd also have to weigh whether they'd be putting too much on their young secondary by asking them to learn a new set of coverage responsibilities in a scheme that offers more variety -- but also more potential for confusion -- than a 4-3.

With Jared Allen about to hit free agency, though, the Vikings don't have big money tied up in a player who would likely be incompatible with a new defense. If they got a new coach who wanted to make the switch, they'd at least have some pieces in place to give it a shot.