Tyson Fury has split with trainer Ben Davison just two months out from his proposed rematch with Deontay Wilder.
Davison played a key role in helping Fury rebuild his career after his suspension, his rise back to the top highlighted by a thrilling draw with Wilder last December.
The pair are set to square off again in Las Vegas on February 22, but the Briton will now have to search for a new trainer to lead him into that fight.
Responding to reports of their parting, Davison wrote on Twitter: "Obviously it's not gonna stop until there's an answer.
"Tyson and myself had to both make decisions for our careers, which resulted in our working relationship coming to an end.
"HOWEVER, we remain friends and he will SMASH the DOSSER!!"
Since surviving two knockdowns against Wilder, Fury has gone on to claim successive victories over Tom Schwarz and Otto Wallin.
Wilder, meanwhile, has successfully defended his WBC heavyweight title with knockouts of Dominic Breazeale and Luis Ortiz.