Tyson Fury has abandoned plans to fight in London on 5 December.
The world heavyweight champion, who has not fought since beating Deontay Wilder in February, had been expected to confirm a bout against Germany’s Agit Kabayel.
But on Sunday he said he would now not return to the ring until 2021.
“The Gypsy King is returning in 2021. Only those that have supported me 100% since my comeback will be with me for the glory,” Fury wrote on Twitter.
Last week, Deontay Wilder called on Fury to “honour his agreement” for a third fight.
Fury had said Wilder will “never get a shot” after the American accused him of putting “something hard” in his gloves before their February bout.
Fury beat Wilder in Las Vegas to win the WBC world heavyweight title, 14 months on from them fighting to a draw.
A trilogy fight was due to take place during the summer but delays led Fury, 32, to seek other plans and state their rematch clause has lapsed.