Mike Tyson is 'stiff and uncoordinated in so many aspects of training', according to his former trainer Brad Rowe.
The boxing legend is currently preparing for his showdown with Jake Paul later this year, with the two men due to lock horns in Arlington, Texas, on July 20.
It will be Tyson's first fight since his exhibition with Roy Jones Jr four years ago.
And Rowe, who trained him for that battle, has compared the 57-year-old to a 'unicorn' while also saying he can be 'stiff and uncoordinated in many aspects of training'.
"Mike is a unicorn," he told USA TODAY Sports.
“He is stiff and uncoordinated in so many aspects of training.
"Then when he enters the ring he turns into a ballerina. It’s unexplainable."
Rowe also revealed that, when Tyson first started training for the fight with Jones, he encouraged the boxing legend to ease himself into running exercises.
Ever the maverick, however, Iron Mike had different ideas.
“Day 1 he’s like, ‘No, f**k you. I’m sprinting,'" he added.
“So I was like, ‘All right. Let’s pray for no injuries today."
The former bodybuilder added: “We’d go to this tennis court and he would like jog around the corners and sprint the straightaways and I’d be, like, I didn’t want him doing it.
“Because especially with someone older, an athlete like that that’s not used to that explosive moment."
It'll be fascinating to see how the fight between Tyson and Paul plays out later in the year.
Many have been critical of the pair for agreeing to a bout due to the huge 30-year age gap between them.
Boxing promoter Eddie Hearn, speaking earlier this month, branded the showdown 'disgusting'.
"I think we live in a crazy world, don’t we, where that younger generation is built off views, built off narrative, built off controversy," he told Piers Morgan Uncensored.
"And as a hardcore fight fan, someone who has been around boxing since I was nine years old, I find it disgusting that a 58 year old man - who was my hero growing up, firstly has to even get back in the ring, from a financial point of view with the amount of money that man was paid or partially paid during his career, to get in a ring with a 25-year-old guy who can’t really fight.
"But for me I understand it and I was speaking to the Netflix guys, I don’t think they liked my criticism of the event.
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"I’m never going to lie to you, I’m never going to sugar coat it, I’m just going to give you my honest opinion.
"Which is, it will sell, people will watch, it’ll be a big event and I don’t like it."
And Ricky Hatton last month said the announcement of the fight would have boxing icons 'turning in their graves'.
“I get the pushing and the shoving and the name calling and holding each other back, but some of the great champions of old will be turning in the grave watching that c**p to be honest with you," he said.
"I’ll be turning in my grave and watching it myself.
"But, I’ve got my eyes open in the sense that this is the world that we’re in now.
"We’re in the entertainment business. YouTubers against MMA and MMA against boxers, I think that world can exist.
"As long as fights like Garcia, Crawford and Spence, Fury and Usyk happen. As long as those fights are made, they can stay in their world and we’ll stay in our world.
"Both can exist, I’m not turning around and saying, ‘oh, this is a joke’. We’re in the entertainment world, that’s the reason why they [YouTubers] have the followings they have, because people want to see it.
"But let them have their world and we’ll have our world.”
