Anthony Joshua could wave goodbye to the sport after a long-awaited British heavyweight battle with Tyson Fury, says Barry Hearn.
The 36-year-old former world champion has opted not to take an immediate rematch with Daniel Dubois following his shock fifth round knockout defeat at Wembley in September.
But Joshua is expected to target a fight with Fury next year, regardless of whether his British rival wins or loses a rematch with Oleksandr Usyk in Saudi Arabia on December 21.
Hearn, president of Matchroom Sport, who promote Joshua, believes that Joshua and Fury both could be tempted to retire after they finally share the ring, preferably in two lucrative fights.
Asked if Fury could be a 'farewell fight' for Joshua, Hearn told Sky Sports: "If he got beat, without a doubt.
"What I don't know the answer to is [what happens] if he beat Tyson Fury.
"If it came about, because it is so humongous and we do have a responsibility to British fans as well, my own personal feeling and it is not going to make the decision for Joshua, is that should be two fights.
"It should be one in Riyadh, one in Wembley and then both can sit down and say 'do you fancy any more or have we made enough'.
"I don't know what will happen because these are warriors, they are not normal people.
"Their burning desire is to be champion, both of them, but our burning desire is to supply fights that the British public want to see and there is no fight bigger.
"Irrespective of belts, there is no fight bigger than Tyson Fury and Anthony Joshua."
Dubois is set to defend his IBF title next against Joseph Parker in February instead of Joshua after Fury and Usyk fight for the WBC, WBA and WBO belts.
But at this stage of his career, Joshua is targeting a legacy fight against Fury rather than another world title reign.
Barry Hearn added: "Now we have the interesting situation of saying what happens next? We have these scenarios with characters and it is a complete soap opera heavyweight boxing.
"You have got characters and narrative at every stage. Tyson Fury, whether you love him or hate him, he is a great fighter, huge personality.
"You have got Oleksandr Usyk who is fighting for his country then coming up you have got Dubois.
"Dubois is taking on Parker. Parker is a very, very undervalued asset. He is a good, good fighter and on his day, he could give Dubois a beating.
"But does Dubois hit him? And if he hits him as hard as AJ, no one is going to stand up.
"So then you have people like Anthony Joshua in the background saying 'I am going to make a decision on my career'.
"It is a pivotal point in his life. He has made a huge amount of money but he is coming up for 36.
"It is a tough loss to take on. As the warrior that he is, he will want to avenge that loss but he also doesn't want to finish his career until he has shared a ring with Tyson Fury because we have been talking about it for 10 years."
