Anthony Joshua could be forced to vacate either his WBO or IBF world heavyweight belts after both organisations named mandatory challengers.

Former undisputed cruiserweight champion Oleksandr Usyk is the WBO’s mandatory, while the IBF named Kubrat Pulev as theirs.

Joshua’s promoter Eddie Hearn wants his fighter to defend both belts, with a view to securing a unification bout with either Deontay Wilder or Tyson Fury but the Matchroom chief has revealed that one of the titles may need to be vacated.