Time of Possession...again

I know this has been discussed already, but I just can't understand anyone who says time of possession doesn't matter. You can't convince me that if the defense is on the field for 5 straight minutes, as they were with Indiana's opening drive, and then on the field a minute earlier, after Michigan's big play, that that won't make them tired. Being tired affects how you play, plain and simple. I think this is especially important with Michigan, when they have so little quality depth on defense. I like that Michigan's offense can score quick at times, but it does concern me that our defense, and again especially given our lack of depth, is on the field so much. I will always believe being on the field more means more fatigue, which means they don't play quite as well.