Wladimir Klitschko has branded David Haye a "liar" and a "loser" and questioned his claims he will retire this year.
WBA champion Haye last week said he was "done" with Klitschko and his brother Vitali, after talks over a heavyweight unification bout broke down when Wladimir agreed to fight Dereck Chisora on April 30.
Thirty-year-old Haye has vowed to retire when he turns 31 in October, and had hoped to fight Wladimir on July 2.
But he says he can no longer do that as a result of the Chisora date, while Klitschko is now in talks to fight Tomasz Adamek in September.
Klitschko, though, insists Haye can side-step his mandatory challenger, Ruslan Chagaev, and then face him in July.
Speaking to ESPN, he said: "I don't take David Haye as a super-special fight. I don't need a half a year to prepare for this fight. I'm always in shape anyway.
"Me fighting Chisora first is good promotion for the fight with David Haye because the guy is also British and very loud. It's perfect to help promote the big fight.
"He could give Chagaev step-aside money and then I'm going to be there with nobody to fight. Because of our history before, I would fight him July 2 and we would work on the contract, but I would fight Chisora first and make sure I fight.
"There have a been a lot of lies from David Haye and (trainer) Adam Booth. We found a date, July 2, to fight him, but I don't trust these guys any more."
Haye claimed last week that if Klitschko did not fight him before his retirement date, the Ukrainian would be forever linked with failing to fight him.
But Klitschko does not believe Haye will end his career this year as he will not want his legacy to be his one-sided win over Audley Harrison.
He said: "He's telling everyone, 'I'm going to retire by the end of the year and I will have my legacy'. He's going to have a legacy for the Audley Harrison fight - the most exciting heavyweight fight in history.
"He has no legacy whatsoever. He has this terrible disease and he has to retire? What bulls**t is that? This is total nonsense. He is playing the media. He will not retire because he's a liar, liar, liar. From the beginning to the end, he's a loser liar. That's the truth about this man.
"David Haye is a piece of s**t. He has accomplished nothing in the heavyweight division other than to present himself with his stupid t-shirt and comments.
"This guy will eventually fight me. He will eventually fight me because everything coming out of his mouth is a lie. But if he does retire, he'll be a loser with no legacy in the heavyweight division at all."
Adamek has revealed on his official website that he is expecting to fight Klitschko this year.
He wrote: "Everything points to an agreement being signed for a fight with Wladimir Klitschko."