Artur Beterbiev’s light-heavyweight title defence against Callum Smith has been postponed after the champion suffered a bone infection in his jaw.
Beterbiev, the holder of the unified WBC, WBO and IBF titles, was due to box Smith on August 20 at Videotron Centre in Quebec City, Canada.
But he underwent surgery earlier on Sunday in Montreal to treat the bone infection in his jaw.
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A scheduled date for the contest should be announced in due course.
Beterbiev, with a 19-0 (19) record, who resides in Montreal, is boxing's only world champion with a 100 per cent knockout ratio.
Most recently he beat Britain's Anthony Yarde in London.
Liverpool's Smith was formerly a world champion at super-middleweight.
Smith won the World Boxing Super Series when he beat George Groves and has only lost once before in his career. That was against Mexican superstar Canelo Alvarez, when he dropped a points decision in a 2020 title unification.
Smith has won two subsequent bouts at light-heavyweight by stoppage and positioned himself as the mandatory challenger for Beterbiev's WBC belt.