Haye claimed a fifth-round knockout win over Monte Barrett in November
David Haye's bout with Vitali Klitschko is off, but the Briton could fight Klitschko's brother Wladimir instead.
Vitali had agreed to fight on 20 June in London but the Ukrainian looks set to make a mandatory defence of his WBC heavyweight title on 31 March instead.
IBF and WBO champion Wladimir has a proposed defence against Chris Arreola in March but it has not been finalised.
"They've stopped spinning the coin and decided it's going to be Wladimir," said Haye's trainer Adam Booth.
"The talk in the first instance was about Wladimir but then big brother stepped in. But now it looks like big brother's stepped back out again so any disappointment that David's feeling at not getting Vitali is going to be taken out on Wladimir.
"We're looking at the summer and obviously there's a few things to finalise, firstly the conversations with the Klitschkos themselves. But everything's moving on quite quickly now."
Former undisputed cruiserweight champion Haye, 28, won his second fight as a heavyweight against Monte Barrett in November, and could line up a bout with Wladimir, 32, within the next fortnight.
Vitali's mandatory defence against challenger Juan Carlos Gomez had always been an issue with the 37-year-old agreeing to fight Haye despite the WBC maintaining he must grant the Cuban a shot first.
Wladimir, who is marginally smaller than his brother and who has been knocked out three times, has always been the preferred target for Haye.
Vitali has only lost two fights, the first when he was forced to retire with a shoulder injury against Chris Byrd in 2000, the second when he was stopped on cuts by Lennox Lewis in 2003.