Michigan football coach Rich Rodriguez says he wants his struggling defense to get bigger, faster, stronger and more athletic.

For two defensive players in role transitions — redshirt sophomore middle linebacker Kenny Demens and sophomore defensive end Craig Roh — such athleticism has been the difference-maker.

“He can do a really high back flip, not just a back flip,” redshirt junior defensive end Ryan Van Bergen said of Demens on Monday. “I think he can clear five feet, easily.”

The 6-foot-1, 250-pound linebacker has injected energy into the Michigan defense since supplanting senior Obi Ezeh in the starting role against Iowa on Oct. 16. Ezeh had manned the position for most of three years.

“He’s just explosive,” Van Bergen said. “His quick movements, you don’t see that with somebody his size. And the way he does it is why he’s good at linebacker. … The runner could be full speed and he could be standing still and he can stop the runner cold. Just because he’s so explosive he can meet your velocity so quickly.”

Since Demens took over the starting role, according to Van Bergen, his relationship with Ezeh has not changed. The two middle linebackers still talk on the sidelines in between plays. Now it’s Ezeh rotating in for Demens, who recorded eight tackles against the Hawkeyes, 12 against Penn State and 10 against the Fighting Illini.

“(Demens) understands the game real well,” Van Bergen said. “The game sorts out for him real fast in his head and he makes decisions quickly. When he tackles, he tackles with bad intentions. It’s something you look for in a middle linebacker.”

Rodriguez has criticized the defense’s tackling and identified it as one of the basics that Michigan needed to work on, but noted that Demens has been consistent in that department so far — particularly in the Wolverines' 67-65 overtime win against Illinois on Saturday.

Demens's unique blend of size and speed allows him to both fill holes quickly and track down opposing ball carriers from sideline to sideline — then make them feel the hit when he gets there.

With Demens making an impact at linebacker, Roh moved to defensive end opposite Van Bergen. The move was such a success on Saturday that Rodriguez said it will probably remain that way for the rest of the season.

In 2009, Roh had 7.5 tackles for loss and two sacks as a true freshman at outside linebacker and was considered one of the best candidates to replace Brandon Graham’s production as a pass rusher this season.

But so far this season he has just 3.5 tackles for loss and half a sack, with most of that production coming early on. For Roh, the position change removes the other responsibilities required of linebackers like dropping into pass coverage and allows Roh to just do what he does best — rush the passer.

Van Bergen approved the move of Roh to the defensive line. He sees Roh's speed is a nice complement to his own power.

“I just felt there was a lot more pressure coming off the edges," Van Bergen said of the defense. "I thought the quarterback was very uncomfortable. He had happy feet back there. We didn’t register a bunch of sacks but he was running for the sideline pretty quickly and unable to find receivers.”

After the game, Roh said he felt more comfortable at defensive end.

Michigan has struggled getting pressure on the opposing quarterbacks consistently all season — the Wolverines’ 1.33 sacks per game ranks 98th in the Division-I FBS football. Moving Roh could jumpstart the pass rush.

“We were just talking about maximizing our guys’ potential,” Demens said. “Craig Roh is a rusher. He does well on the line. He’s not too bad at linebacker, but he maximizes his stuff on the line.”

For a unit that has allowed 34 points per game, it couldn’t hurt to let it rip — and watch Roh and Demens fly to the ball.