Heavyweight boxing legend Evander Holyfield will end his 28-year professional career if he fails to line up a fight by the end of the year.
Four-time champion Holyfield, 49, has not fought since beating Brian Nielsen in May 2011, when he repeatedly called out WBC champion Vitali Klitschko.
"If I don't get a fight lined up by this year, I retire. So, don't nobody fight me by the end of this year, that's it for me," he said Tuesday while attending an open training session here for WBA regular champion Alexander Povetkin.
Klitschko has reportedly said he will not fight Holyfield because the American was his hero in his youth.
Holyfield insisted he was still capable of beating both Vitali and Vladimir Klitschko, who hold all four major titles between them.
"The thing is, I believe that I could beat them, either one of them," he said.
"I believe that I have the knowledge. They're very knowledgeable fighters, they're good thinkers, so you've got to out-think the thinker."
"The thing is that I see the fights they fight and I think that I could make the adjustment that's necessary to be able to win."
Holyfield has fought only three times since losing to Nikolai Valuev in his last title fight in December 2008.
His professional record stands at 44-10, with 29 victories by way of knockout, as well as two draws and a no contest.