Greg Mattison knows a thing or two about how defenses are supposed to play at Michigan.

He's coordinated at the program in two different eras. He helped build the school's most successful defense of the modern era in 1997. He helped turn around one of the school's worst defenses in 2011.

He knows what elite-level defenses are supposed to look like. And, at the same time, he knows what they aren't supposed to look like.

A year ago? Michigan was the latter. And as spring football moves forward, Mattison says he's feeling some urgency to get his defense back on the right track.

"I always have a sense of urgency," said Mattison, who will be back on the field this week with the team as it resumes practice following spring break. "You've heard me say it a lot of times, and I really believe this and I always will.

"The bar was set here a long time ago with how you are supposed to play on defense. And if you don't play that way? You could call it urgency."

A year ago, Michigan didn't meet that bar.

The Wolverines finished the year No. 41 in total defense, No. 66 in pass defense -- the lowest the unit has been during Mattison's three years with Brady Hoke.

Michigan's defense, in Mattison's estimation, allowed too many big plays (53 plays of 20 yards or more), didn't create enough pressure on the quarterback up front (11 1/2 sacks from defensive linemen) and seemed to slip late in the season -- notably against Ohio State and Kansas State.

The Wolverines were far from a wreck on defense in 2013. Even with the subpar showings against Ohio State and Kansas State, Michigan still finished No. 29 nationally in rush defense. But, again, not good enough per Mattison.