Frank Clark (57) closes in for a tackle on running back Justice Hayes during the Michigan spring game. Clark and Brennen Beyer are in a battle for the starting weak-side defensive end position.

Melanie Maxwell | AnnArbor.com

One of the Michigan football team's primary objectives during the spring was to cobble together a defensive line rotation after it shed three starters from a season ago.

But while tackles Will Campbell and Jibreel Black drew much of that attention to the interior, there was a quiet battle brewing at weak-side end between sophomores Frank Clark and Brennen Beyer.

It turned out to be the defense's fiercest job battle of the spring.

The Wolverines were deep at the position last year, when Craig Roh and Black combined for 50 tackles and 5.5 sacks. But Roh has since moved to strong-side end, replacing Ryan Van Bergen, and Black to tackle, replacing Will Heininger.

That leaves Beyer, who played strong-side linebacker last year, and Clark to man the position.

Beyer earned the start for the spring game last weekend, although defensive coordinator Greg Mattison said not to read too much into that.

Brennen Beyer

Frank Clark

"They haven’t separated themselves," Mattison said. "I have been very pleased with the two of them, and how hard they’ve worked and how hard they’ve tried to improve on what we say they need to improve on.”

For Beyer, that mostly means learning how to stay low.

There isn't a drastic difference between playing strong-side linebacker and weak-side end, at least in terms of assignments and responsibilities. The ends work in concert with the outside linebackers, so Beyer already had some familiarity with the position before making the switch.

He also lined up with his hand down during practices last year.

The biggest adjustments for him are adapting to the speed of the game up front, and learning the fundamentals of the position -- such as hand and footwork, as well as pad level.

"Beyer is a very strong football player and can run," Mattison said. "What Beyer has to work on a great deal is he gets a habit of getting high. He’s got to stay lower. Then he’s going to be a real force, I think."

To that end, Clark has a step on Beyer. He's played the position, dating to his days at Glenville High School in Ohio, and has been praised for his athleticism. The world was introduced to that in the Sugar Bowl, when he made a superb interception of Virginia Tech quarterback Logan Thomas.

Sometimes, though, Clark gets a little too aggressive because of that athleticism.

"(Clark) wants to run to make plays before he beats the block, at times," Mattison said. "He needs to take some of what Beyer does, and Beyer needs to take some of what he does."

Both have work to do, and neither likely will be as disruptive as Roh next year. But on a defensive line devoid of depth, and three playmakers stacked at weak-side end, it makes sense to spread out the talent.

By moving Roh and Black, the line is better positioned as a unit to compensate for the losses of Van Bergen, Heininger and Mike Martin.

“I feel very comfortable with the moves -- very comfortable," Mattison said. "I think that might be one of the bright spots of the spring.

"The combination of Beyer and Clark gives us a lot more athleticism on the edge."

Kyle Meinke covers Michigan football for AnnArbor.com. He can be reached at 734-623-2588, by email at kylemeinke@annarbor.com and followed on Twitter @kmeinke.