I think Khan had nothing left to prove after he beat Kindelan, who came out of retirement to fight him, but still that is one of CUba's best fighters ever, and Khan beat him so what else was there to prove? Rau Shee Warren lost to the current second best amateur in the world in the second round of the last games, but they haven't fought in awhile, and Warren and this guy ,Zou SHiming, are both expected to be the best fighters in that weight class