The two former world heavyweight champions are both back in the ring this weekend in what are being seen as must-win warm-up fights before their expected "Battle of Britain".
Fury will face Poland's Mariusz Wach in Pattaya, Thailand, while Joshua takes on Albania's Kristian Prenga in Jeddah, Saudi Arabia.
Although the date and venue for their proposed November fight are yet to be confirmed, it is expected to be the first time the British rivals finally meet after years of failed negotiations.
Fury recently told Sky Sports he was prepared to fight "somebody else" later this year, raising doubts about whether the highly anticipated clash would happen.
However, Hearn rejected those comments, saying Joshua has never pulled out of a fight and pointing out that Fury previously withdrew from their planned bout because of an arbitration ruling involving Deontay Wilder.
Hearn says the only thing likely to prevent the fight from going ahead in November is if either boxer loses or suffers an injury in their fights this weekend.
Joshua's fight will be his first professional bout since a car crash in Nigeria in December claimed the lives of his long-time rehabilitation coach Sina Ghami and close friend and personal trainer Latif "Latz" Ayodele.
Speaking to the BBC, Joshua admitted he is still struggling to come to terms with their deaths, saying the pain remains and he keeps himself busy because he is not yet ready to fully process his grief.
Tomorrow's fight will also be Joshua's first competitive bout since his knockout defeat to IBF world heavyweight champion Daniel Dubois in September 2024.
Source: Super Sports
