Deontay Wilder believes Anthony Joshua "froze" against Andy Ruiz Jr because he couldn't handle the pressure.
Joshua was dropped four times before he was stopped in the seventh round by the Mexican-American last month.
He lost his three heavyweight world titles and saw a £50million pay day against Wilder go up in smoke.
Joshua will have the chance to win back his belts in the rematch to be held later this year, but Wilder was not shocked he lost in New York.
"AJ had a lot of pressure on him coming to America for one, and then he was worrying about me and what I did in my performance," he told World Boxing News.
"All that stuff weighs in on you. He was panicking in the dressing room and I understand all that stuff, it’ll get you.
"Certain things, you want to perform and do great. Nobody never wants to lose. We want to do great, but when we got so much on you and so much pressure, talking about the sparring guys dropping him in sparring and stuff, it’s a lot.
"When your time comes I understand he just froze at the moment of time, but we’ll see whether he can redeem himself in the second fight.
“I wasn’t shocked at all. I said it was going all 12 rounds, but don’t be surprised if Joshua loses either."
Ruiz, meanwhile, has said he will be even more prepared for the rematch.
He said: "The rematch is going to be the same. I am going to be more prepared and more ready.
"I know his flaws. I can do a lot better. The only thing that he can do is just run around, he's not good at boxing."
