Mike Tyson's new boxing coach was left fearing for his life when he took the former heavyweight word champion on the pads.
Tyson, 53, is planning to return to the ring to take part in exhibition bouts, 15 years after his final professional fight.
He has been training with coach Rafael Cordeiro who is renowned for his work in mixed martial arts.
And he told ESPN: "As soon as we started training I said ‘My Lord'. I didn’t know what to expect from a guy who hasn’t hit mitts for – I think – almost ten years.
"So I didn’t expect to see what I saw – I saw a guy with the same speed, the same power as a guy who is 21, 22-years-old.
"And I can tell; you would have to be a good guy to spar with Mike, because if you don’t prepare, he is going to drop you for sure – 100 per cent.
"The power is different level. I have trained a lot of heavyweights in my career, with not a lot of respect for everybody, but he is almost as powerful as Wanderlei Silva is right now.
"When you talk about power, I held his right hook and thought ‘he is going to kill somebody’."
“When I hold mitts, I like to hold them close to my face and the first time, I saw his right hook and I saw my whole life [flash before me].
"My wife, my daughters, my dog – I see everything because I thought, ‘I’m going to die here’.
"But it’s just the fear; every time I hold mitts for him and he threw any kind of combination, it would push me off of the mat.
"He puts on pressure, pressure, pressure. Mike Tyson’s game, as everybody knows, is pressure. Same way he fights, is the same way he trains."
Cordeiro did, however, play down talk of a professional comeback.
"I don’t know,” he added. “But I can tell you; if he wants to do something in the future, he is going to be ready to do that – 100 per cent.
"I don’t want to say too much because it’s Tyson man. We can’t play with this guy."
