I think Michigan has a *lot* of receiving options with high end Big Ten potential:
Black, DPJ, Nico Collins, Oliver Martin, Perry, Zach Gentry, Nick Eubanks and Sean McKeon (this last one, Mdot may scoff at but I thought he played well and the fact that nearly by himself he pushed Ian Bunting to transfer was very meaningful to me)
Unfortunately, on that list, I think only DPJ and Tarik Black can be elite blow-the-top-off-the-defense types like Breaston/Manningham. The rest are built - if they can get there - would only max out in the Jason Avant or Jake Butt mode (or maybe more Travis Beckum in the case of Gentry).
If Michigan loses Black, even just against ND, it's a massive deal. Having two guys to take the top off is **way** more than twice as good as having one.