Vitali Klitschko's manager Bernd Boente has revealed that he is in discussions with David Haye's representatives over the widely-speculated bout between the two fighters.
The British former heavyweight champion, who confirmed his retirement last month, has been given a three-week deadline to decide whether he wants to take up the challenge, according to the Daily Star.
"It's the biggest heavyweight fight out there, one that would stir the public's imagination," Boente said.
"There is no other fighter that would bring British TV. Tyson Fury (British and Commonwealth champ) is not interested in fighting either of the brothers.
"We are in talks and Haye said he would come out of retirement to fight one of the Klitschko brothers."
Despite Boente's confidence, Haye's manager Adam Booth recently denied claims that the fight will go ahead.