They had 9 wins last year in the Big 10 and their strength is their D line. If their D line dominates our O line, which isn't out of the question (see Wisconsin film), our O may not get on track and our D, unless improved, may not be able to hang with them even though they're breaking in a new system.
Not saying that will happen, and sincerely hoping it won't, but they're at home with a 29 game win streak and we've seen the wheels fall off for BYU recently (last year's USU game, BSU game, etc.).