Sterling explains why he turned down a rematch with Petr Yan

Aljamain Sterling, the UFC lightweight champion, explained why he turned down a rematch with Petr Yan.

"Training is going well, but I'm having a hard time even two rounds of sparring, because the fatigue and cramps still persist. According to the surgeon, all this is because my nerves have not yet recovered from the surgery I underwent. For that reason, I don't want to ruin the full benefit of the surgery with the risk of an even more serious injury," said the fighter.