Ivaylo Gotzev, who co-promotes Kubrat Pulev with Top Rank, has issued a firm warning that Anthony Joshua is required to fight his boxer next or face litigation.
Pulev is the IBF's mandatory challenger to Joshua, who also holds the WBA, WBO, IBO world titles.
Joshua and Pulev were scheduled to fight each other in June, but the fight was pushed back due to the coronravirus pandemic.
At the moment, as reported by BoxingScene.com, there is a tentative date of December 12 for the fight.
But Pulev's handlers are a bit concerned that Joshua will attempt to go around them to make a full division unification with WBC world champion Tyson Fury.
That scenario is unlikely, as Fury is also co-promoter by Top Rank, who would certainly look out for their other client Pulev.
If the Joshua-Fury scenario is even attempted, Gotzev says a lawsuit will be initiated.
"[The Joshua-Fury] door will be closed with a lawsuit if they break our deal and our contract. There are some very good attorneys in England and some very fair courts, so it will come down to whether they want to decide whether they want that or not. I do believe AJ and his promoter will do the right thing and do as they say and finalise the deal," Gotzev said to Press Box PR.
"Through blood sweat and tears Kubrat earned his position to challenge AJ. Will they overrule his rights, can they all overrule his rights? That's entirely up to them if they want to try that. They should respect the rules of the IBF. There's a signed agreement.
"We are in the final stages of closing the deal, which we are extremely happy with. We're adjusting the original contract and it's finally going in the right direction that keeps both sides happy. It's now up to [Joshua's promoter] Eddie [Hearn] to conclude their part. Our signature will come a lot easier than theirs. To become a champion you must go into foreign lands and conquer and that's what Kubrat has decided to do. That's where the win will be the sweetest and the most legitimate. Let's do it in London.
"We're going for the knockout. Kubrat is a man's man. He has heart, skill. talent and he's going to upset the apple cart. The question is: is AJ a man or is he still a mama's boy? Kubrat is the big underdog, it's like a Rocky story. AJ is a physical specimen, he's like Apollo Creed and we're bringing in Rocky. When he upsets AJ that's the end of Matchroom's reign."