Brock Lesnar was once a force to be reckoned with in the UFC Heavyweight division and then, as if he was never there, poof he was gone. Brock Lesnar had some hardships to overcome, such as his bout with diverticulitis, which is a very painful stomach disorder that he was living with until he needed emergency surgery to correct it. After he came back something seemed off with Brock and him taking a few punches seemed like the end of the world to the once crazy beast that ruled over the division.
According to Brock Lesnar’s trainer, Greg Nelson, Brock’s issues were mental, not physical, as he had some hurdles to overcome. He still believes in Brock, though. [source]
Nelson said he thought Lesnar could still be successful in the UFC.
“I believe so,” said the trainer. “If he came back and he was 100-percent mentally in the game, knowing that he could take whatever it meant to take, he could push himself, he could get hit, he could whatever – that was the big thing. When he was mentally on, I mean, literally, like his moniker when he was a college wrestler, he was like a freight train. He just was going to go through anything. If he came back and he was mentally 100-percent there, I believe physically he still has the gifts and he still has the ability to improve and to grow, but it’s like anything. The game is such a mental thing that once that chink in the armor was there and that kind of embedded itself in his head, I think that was really the point where it was tough for him.”