World heavyweight champion Tyson Fury will never fight again, leading British promoter Eddie Hearn has said.
Fury, 28, has withdrawn from his rematch with Wladimir Klitschko, scheduled for 29 October, because of reported mental health issues.
The Englishman, who has not fought since beating Klitschko last November, postponed the original rematch in June.
"Fury will be stripped of his titles and, after a legal battle, he'll say: 'No more, I'm done'," said Hearn.
"It's going to be really messy and it might take a year to resolve. I know there are sensitivities around mental health issues but this is a business.
"The governing bodies have had enough. The world heavyweight title is a huge part of their business and they've not made any money from it for a year."
Fury beat Klitschko on points in Germany - the Ukrainian's first loss since 2004 - to pick up the WBA, IBF, WBO and IBO titles, with American Deontay Wilder holding the WBC belt.
Within two weeks Fury was stripped of the IBF title because he was unable to fight mandatory challenger Vyacheslav Glazkov - and that belt is now held by Fury's fellow Briton Anthony Joshua.
Too early for Joshua?
Hearn, who does not promote Fury, said Klitschko's team - including manager Bernd Boente - were keen for the 40-year-old to fight his own man - Joshua - on 29 October.
But Hearn believed the predicted legal challenges from Fury's team made that match unlikely.
"I spoke to Bernd Boente for half-an-hour on Saturday and the conversation was great, we all fancy the fight," said Hearn.
"It does feel a little bit early - Joshua has only had 17 professional fights and Klitschko's experience worries me. But he looked awful against Fury. I think he's done."
Joshua, 26, is scheduled to defend his title in Manchester on 26 November.
Hearn added: "We're fighting in nine weeks, so we need to announce an opponent next week.
"I think the WBA and WBO would sanction the fight and the deal would be easy to do. But Fury's legal battle to keep the belts will take too much time."
Hearn said Joshua is more likely to make the second defence of his title against mandatory challenger Joseph Parker, from New Zealand.
Fury the champion in recess?
Hearn believes the WBA and WBO will both make Fury their 'champion in recess', meaning Klitschko could fight for the vacant titles in October before facing Joshua in a unification showdown next spring or summer.
If Fury's team do take legal action, and the governing bodies' hands are tied, it would leave Klitschko in limbo.
On Sunday, Fury's uncle and trainer Peter said his charge's medical condition was caused by a "witchhunt" conducted by the British media in the wake of his stunning upset of Klitschko, who had not lost for 11 years.
But Hearn believes Fury's team will not be able to persuade the relevant governing bodies their fighter should hang on to his titles indefinitely.
"If they just say, 'he needs time away from the sport', they're bang in trouble," said Hearn.
"The governing bodies will ask: 'When will he be ready to fight?' And his doctor won't be able to tell them. Once they hear that, they'll make him champion in recess and say: 'Once you're fit, we'll give you another chance.'"
Fury is under investigation for alleged doping, having been charged with an offence by the UK Anti-Doping Agency (Ukad) in June, after traces of a banned substance were allegedly found in a urine sample.
The fighter has denied allegations of doping.
It has also been alleged he recently refused to give a sample, having been visited by Ukad. An athlete who refuses to take a drugs test can be banned for four years.
While Hearn stressed he had sympathy for Fury's health issues, he added those around him must take their share of the blame for his plight.
"How can you unify the heavyweight division by beating Wladimir Klitschko in Germany and mess it up so badly?" said Hearn. "You couldn't make it up and the people who guide him have to be held responsible for what has happened.
"I wanted Fury to fight Klitschko, because we wanted Joshua to fight Fury. A heavyweight world title unification between two Brits is gold dust. But everyone in boxing knew that the fight between Fury and Klitschko wouldn't happen and I don't think Fury will fight again.
"Some people can't deal with being in the spotlight and maybe he thinks he'll never get that feeling again that he got from winning the world title."