Eddie Hearn has warned Anthony Joshua not to repeat the mistake he made against Andy Ruiz Jr by giving his undivided attention to Oleksandr Usyk.
Joshua was originally supposed to fight Tyson Fury in a world title unification fight this summer but the Gypsy King was forced to pull out and take on Deontay Wilder in their trilogy clash instead.
'AJ' now has to avoid defeat in the second defence of his world titles against Usyk in September to set up a showdown with bitter rival Fury.
And Hearn has warned Joshua not to repeat the mistake of allowing his focus from his upcoming fight to be affected as it was by Deontay Wilder.
"Do you know what, I think right now, let's just forget about that fight," Hearn said to Sky Sports.
"The only good thing to come out of this is that we have two good heavyweight fights. These aren't marking time fights for Fury and AJ. These are two competitive, dangerous fights.
"This summer, you've got Fury-Wilder and hopefully AJ-Usyk as well. Two good heavyweight fights.
"Once those two nights are complete, let's go back to where we kicked off before, because right now, there's no conversations from the other side to us saying, 'Let's just get it in the diary for December or January.' I don't really want to get into that conversation. I want AJ to focus on Oleksandr Usyk.
"Any work that takes place will go on behind closed doors, but we can't make the same mistake that we made against Andy Ruiz, which was, 'We just want [Deontay] Wilder, we just want Wilder.'"
Hearn also revealed that he is close to reaching an agreement with Usyk's representatives which would see the two throw down at the Tottenham Hotspur Stadium in September.
"We have both alerted the WBO, myself and [Usyk's promoter] Alex Krassyuk," he added. "Terms are agreed. The offer we made to them has been accepted.
"We move forward to paper that now. We are going through the contract with their team."
While Hearn is wary of Wilder's one-punch power, he believes Usyk is a much bigger threat to Joshua.
He continued: "In the Wilder fight, technically he's not a danger for one second of the fight. He does have the power to switch your lights off, in one second of the fight.
"Usyk, who is not a tremendous puncher, is probably one of the most technically gifted fighters pound-for-pound. But I think AJ likes that. I think he wants to face that style, but he also needs to be ruthless in that fight.
"Both of those fights very dangerous in their own right and we hope and pray that both the Brits come through."News Now - Sport News