World heavyweight champion Vitali Klitschko has been forced to withdraw from his mandatory defence against Canada's Bermane Stiverne after injuring his right hand in training.
"The champion has stressed he won't be able to fight Stiverne on the date scheduled for his mandatory defence," said the world boxing council (WBC) in a statement with Klitschko having been due to fight Stiverne later this year.
The 42-year-old Klitschko has held the WBC heavyweight belt since October 2008 but the injury means he is now unlikely to box in 2013.
Klitschko, who has 41 knock-outs from 45 wins in 47 bouts, last fought in September 2012 when he enjoyed a fourth-round technical knock-out of Germany's Manuel Charr in Moscow.
The WBC's board of governors will now meet to discuss the situation and Klitschko could be stripped of his world title or ordered to fight before a specified date.
Klitschko had been lined up to meet the 34-year-old Stiverne, who has 20 knock-outs from 23 wins in 25 bouts, after the Canadian's unanimous decision win over Chris Arreola of the USA in April.
Between them, Klitschko and his younger brother Wladimir hold all of the major heavyweight titles in boxing.
Wladimir, 37, will defend his IBF, WBA, WBO and IBO titles against Russia's Alexander Povetkin in Moscow on October 5.
