Boxing promoter Eddie Hearn says Nathan Cleverly and Tony Bellew are likely to fight a cruiserweight title eliminator in Sheffield on 6 December.
But the fight is now likely to be at a neutral venue, possibly on a card with IBF welterweight champion Kell Brook and ex-Olympic champion James DeGale.
"December 6th in Sheffield now looks like a front-runner," said Hearn.
"It's a shame there's not an arena big enough in Wales yet for a fight of that magnitude.
"Nathan is keen, and rightly so, to have it on neutral ground.
"It's more a case of where it's going to be than if it's going to happen.
"It's definitely going to happen."
|Boxing promoter Eddie Hearn on Cleverly v Bellew|
|"The rewards are so big in this fight. They are two great fighters and something has got to give."They just don't like each other but that adds to the fuel."|
Cleverly beat Bellew to retain his WBO light-heavyweight title at Liverpool's Echo Arena in October 2011.
After losing his WBO title to Sergey Kovalev in August 2013, the Welshman announced he was moving up to cruiserweight.
Bellew also followed Cleverly into the division after losing to Canada's Adonis Stevenson in a WBC light-heavyweight title fight in Quebec City in December 2013.
Cefn Fforest's Cleverly stopped Alejandro Emilio Valori on his cruiserweight debut in July 2014, on the same Liverpool bill that saw Bellew beat Julio Cesar Dos Santos.
The winner of the next bout is likely to qualify for a world title challenge, possibly against WBO cruiserweight champion Marco Huck from Germany.
"The rewards are so big in this fight," said Hearn.
"They are two great fighters and something has got to give.
"They just don't like each other but that adds to the fuel.
"The first one was such a great fight, I think the second time around you're going to see something just as special."