Some of what he said here had been mentioned by a couple of Beterbiev's past sparring partners. One of them being Lionell Thompson. To paraphrase he said, no bullshit, sparring Beterbiev felt like getting hit by a car and he would know because he'd actually been hit by one once. He also said that sparring session was the worst experience of his life. When Mickey says he heard that these sparring partners quit and don't show up to give Beterbiev work despite getting paid well it's because he's constantly hurting guys in sparring. That's not a secret because his own trainer has revealed that. This "bone crushing power" is how they all describe it. Though I hadn't heard that he can't spar full sessions or that he has to wear big gloves when sparring. That's damn scary if it's accurate.