Losing Woolfolk definitely hurts here, because he was a decent tackler, quick and good on runs support.
I think was under no illusion that Michigan's secondary would be bad this fall. They would get torched this fall on a regular basis against the pass. So what I've been most worried about is Michigan's inability the last 3 years to stop anyone on the ground for 4 quarters. UConn, Notre Dame, Indiana, MSU and Iowa will be great early tests for Michigan's run defense this fall. Forcing opponents to throw might yield unhappy results (50+ yrd TD bombs) at times, but a defense unable to stop the run (and the clock) is much worse IMO.
But the Michigan pass defense? We sort of knew that was gonna suck this year, didn't we?