Notebook: Defense building depth 

February, 8, 2013
2/08/13
9:00
AM ET
As long as Greg Mattison is Michigan's defensive coordinator, he will expect perfection. He demands a lot out of his players because he knows what it takes to reach the NFL.

The 2013 class for Michigan is all about getting to the next level and bringing in players who can help Michigan get there.

Defensive line

Jim Harbaugh Joins 'College GameDay'
New Michigan football coach Jim Harbaugh joined "College GameDay" to give coaching advice and shoot half-court shots.
VIDEO PLAYLIST video