Can we really play Humphries at center? He's only 6"9. 
Humphries is listed on some current Celtic rosters as a F-C. I agree he is undersized but he may be the best option we have at the beginning of the season. Better than Bass for sure, Sully may not be ready and isnt really much taller if at all. Humphries is the better athlete as well.
Lots of folks assuming Olynyk will be our starting center. I believe there is a good chance he isnt ready. Not many choices left, Melo?,Favarini?,Randolph? Humphries beats out all of these at the beginning of the season IMHO.
I dont mean to sound like a big fan, I am not, but if Humphries is still on the roster he will likely be our best overall bigman for a while until someone proves otherwise.