Eddie Hearn says he is still working hard on trying to finalise a deal that would see Anthony Joshua fight Wladimir Klitschko.
Joshua is due to defend his IBF heavyweight title on or around November 26 and Klitschko leapt to the front of the queue when his rematch with WBA/WBO champion Tyson Fury collapsed.
Live Fight Night
Matchroom promoter Hearn warned there is still work to be done to get the deal across the line but emphatically ruled out an all-British battle with David Haye, who last week announced he would fight on December 10.
"While you can never put every egg in the basket, most are in there now, saying 'this is next'," Hearn told Sky Sports News HQ.
"Now it's a case of going through the finer points of the agreement and I feel like most of the deal is done but there are still a lot of obstacles that can interrupt our progress.
"They are not really obstacles I feel should stop the fight from happening."
Asked about the viability of Haye as an opponent, Hearn said: "He's not fighting AJ but there are rumours he might go the same night.
"I think that's a fight that's not too far away either but the Klitschko fight is the one that really whets the appetite.
"If we can get a couple of belts on the line, that would be fantastic.
"I just feel like it is the right fight for Anthony Joshua right now. He is committed, his training team is committed, I am committed, and I think Bernd [Boente, Klitschko's manager] and Wladimir are as well.
"If we can make sure everything is right, which I hope it is, then I think we will get there."
Despite the desire to confirm the fight, Hearn insisted there was no cut-off date despite the fact Manchester Arena is booked for November 26.
"As soon as possible is the cut off," he added. "If a deal is going to be done, I think it should be done by the end of this week and if it's not, there is probably going to be a problem.
"Of course we want to announce the fight but, at the same time, fights of this magnitude do take time and you have to make sure all the boxes are ticked."