Theres nothing wrong with it, its just pigmentation. A lot of people with Vitaligo bleach their skin to hide it like MJ, but I commend Rubio for not trying to mask it. On another note, I think he takes Lemeuix the distance.
Yeah that's vitiligo. He also looks about 60 and, more importantly, seems to have trouble making the weight. Lemieux may well flatten him early.