Eddie Hearn expects Anthony Joshua to fight cruiserweight king Oleksandr Usyk next year.
It is anticipated that undisputed cruiserweight champion Usyk will make the step up to the heavyweight division in 2019.
Hearn, Joshua's promoter, says the WBO, WBA and IBF heavyweight title-holder could well do battle with the Ukrainian in a mandatory bout next year.
Asked if the Briton and Usyk might step into the ring together this year, Hearn told Sky Sports: "No. That fight comes in 2020."
He added: "Usyk will fight in May, probably in his heavyweight debut, potentially against Alexander Povetkin.
"Then he'll have one more. Then it looks like the WBO will make him mandatory for Anthony Joshua. I see that fight happening in spring 2020."
Joshua's next assignment is a United States debut against Jarrell Miller at Madison Square Garden on June 1.
