Aleksandar Mraovic has opened up about his experience of sparring alongside Tyson Fury ahead of his heavyweight blockbuster this summer.
Heavyweight's WBC champion is currently training across the pond with SugarHill Steward as he prepares to take on Anthony Joshua.
August 14 will be the fight date and Saudi Arabia will host the showdown.
Despite initially being expected to be announced this week, Eddie Hearn has claimed they will fight in a brand new stadium, which will 'block people's minds'.
Mraovic, 24, was impressed by the condition of the "Gypsy King" and revealed his punches felt 'like rocks'.
"This man is not of this world. He's a different animal," Mraovic told the MyBettingSites.co.uk blog.
"He's punching like a machine. "I have never felt punches like that before from anybody. When we were sparring, Tyson even showed me how he got the power and how he works on it.
"His fists feel like rocks on you when he hits. It's incredible. The power comes from how he punches and how he uses his weight.
"He's in great condition. Tyson Fury never had a bodybuilder's body, but he moves like a real athlete.
"He did twenty rounds, no problem. We were all done after 12 rounds, we did a lot of body sparring, and we were all dead.
"His movement is amazing, and he wasn't even fully fit at the time.
"He doesn't give up. That's how we all know him. He doesn't give up, either in life, neither in the ring, neither in training.
"Fury never gives up. That was his first sparring after the Deontay Wilder fight. He is sick, and he is crazy good.
"He played with me, but it wasn't a serious spar, nothing serious. Right now, I would have no success against him. He's too experienced.
"I think Joshua can't win. I don't think Joshua can survive 12 rounds because, in this era, Tyson is the king. No one can beat him." Mraovic admitted he is excited to showcase his own skills as he prepares to make his professional
"I am the type of fighter everyone wants to see. I want to fight, and you'll see that on my debut. But I want to fight, and I'm a crazy guy. I will be very entertaining for the people."