Representatives of Anthony Joshua and Deontay Wilder are in talks over a two-fight deal next year.
Joshua and Wilder are both fighting in separate bouts on the same bill this weekend.
While the heavyweights will have to concentrate on Saturday's contests, Joshua against Otto Wallin and Wilder against Joseph Parker, their teams will continue discussions about two prospective bouts for 2024, with the first potentially taking place in March.
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Shelly Finkel, Wilder's manager, confirmed to Sky Sports that a deal is not yet done.
"Things can move very quickly," Joshua's promoter Eddie Hearn told Sky Sports. "To lock in a fighters' plans for 10 to 12 months is a really good position for him, especially if it comes with the lucrativeness of a Wilder fight in the Middle East. So two fights is definitely being discussed.
"March is probably the time we can strike for that mega-fight obviously for the financial rewards that you'd look for for a fight with that kind of risk and danger.
"I think there's a lot of things that need to happen. Of course they both need to win. They both need to come out unscathed really. If there are any niggles or any injuries or any cuts, it's very difficult to go back into a March fight.
"It's going to be a very quick turnaround if we were to go on that date but of course if AJ doesn't win, if Wilder doesn't win, it's all irrelevant anyway."
Joshua will have other options. Beating Wallin would put him in line to challenge for the IBF heavyweight title, which is likely to become vacant after Tyson Fury and Oleksandr Usyk box in February.
Fury and Usyk are expected to have a rematch later in 2024 too and so the winner of their fight would not be able to meet mandatory challenger Filip Hrgovic.
In that case the Joshua-Wallin victor could be mandated to box Hrgovic for the vacant belt.
Then for Joshua, Hearn said: "It's a toss up really between trying to become a three-time world heavyweight champion or taking arguably the biggest fight in boxing which is what he's always been about.
"Although he wants to become a three-time heavyweight champion, the lure and the excitement of the Deontay Wilder fight is very difficult to ignore.
"If he adds Deontay Wilder to the resume following Otto Wallin, and maybe lends itself to a fight with Tyson Fury, you would say Anthony Joshua has boxed absolutely everyone of relevance in the heavyweight division during his career and that's a legacy you can never undo.
"Our aim, our vision, and I can see it, is he beats Deontay Wilder and then he beats Tyson Fury. And if he does that he probably goes down as the greatest heavyweight of our generation."
As for Wilder, he didn't want to say too much about Joshua in the press conference ahead of the Day of Reckoning fight this Saturday.
"I see a man that's been focusing on the test that lies in hand. I'm not in his head so I can speak for himself," said Wilder on Joshua.
"A lot of people have asked me about his mannerism, his demeanour and the way he's been reacting to the media and the questions when they come about me. I can't speak for him. We are on the outside looking in.
"He has a big task to complete and I have one as well. When it's all over we can talk about it. But at this moment in time, it's getting closer to the fight and we are all focused on the same task and that's to win."
Day of Reckoning featuring Anthony Joshua vs Otto Wallin and Deontay Wilder vs Joshua Parker is live on Saturday December 23. Sky customers can purchase on TNT Sports Box Office at www.sky.com/boxoffice/tnt-sports/day-of-reckoning