Usyk cannot KO Joshua. Simply can't. He doesn't possess the power nor the momentum to knock out a strong specimen like AJ. His pitty-pat soft punches can only itch Joshua. I am 100% sure it is Usyk who will gas out, because: 1- He bulked up as he never did before. He is not used to fight in that weight. 2- He has never fought a big and powerful boxer like AJ. Working on him isn't similar to working on Bellew or Gassiev. Thus, he will get exhausted in the middle of the match. AJ gassed in Klitschko match, because Klitschko is also a big and powerful guy, unlike Usyk.