Eddie Hearn described Anthony Joshua as the "golden ticket" of heavyweight boxing and says any potential opponent needs to be "realistic" to fight the Briton, after confirming a bout with Joseph Parker is close to being announced.
A heavyweight unification bout between Joshua and New Zealander Parker has been on the cards for several months, but as yet a date has not been booked in.
WBA, IBO and IBF champion Joshua is targeting Parker and Deontay Wilder, the WBO and WBC belt holders respectively, as part of a blockbuster 2018 to unify the heavyweight division.
Hearn says more talks are due with Parker, but sent out a warning to any rival that wants to face off with Joshua.
"We're getting there. As AJ says, he wants the belts, he wants to be undisputed king of the division," Hearn told Sky Sports.
"That's the aim, and to do that he has to win two belts.
"We're looking at March 24, March 31, and April 7 as potential dates for his next fight, with various different venues in London and Wales, even other venues and cities around Europe as well.
"We want that unification fight, we're close to a deal with Parker - it's not done yet but we hope over the Christmas period, the turkey will get put to one side and we'll work to get that done.
"Hopefully we'll be in position to announce that early in 2018.
"AJ is that Willy Wonka fight - the golden ticket, the one everybody wants. A lot of people are talking 'I want this, I want that' but if you really want it be realistic and come get it."
For his part, Joshua does not mind who he faces so long as a belt is on the line and said Parker's verbal barbs on Twitter do not faze him.
"Every year has to be an increase on what we have just done. I want to go and become undisputed heavyweight champion of the world and 2018 starts paving the way for that," Joshua said.
"Whoever is the first stop off, end of March or early April, so be it. But I do want it to be for a championship belt. There's two left - WBC and WBO. The WB is fine, whether it's the O or C is up to the opponent.
"I don't really get involved in the whole Twitter beef too much but as I have said it does add to it.
"Saying one thing is different to acting. We've been in touch and we're trying to make this fight happen."