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 on 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 is still capable of beating both Vitali and Wladimir 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.” From gulftoday