Vitali Klitschko might have to flip a coin with his brother Wladimir to decide who fights Britain's David Haye.
Haye won the WBA heavyweight title by defeating Russian giant Nikolay Valuev in November and faces the first defence of his title against American John Ruiz next month.
Assuming he wins that contest, Haye has his sights set on unifying the heavyweight division and that would mean defeating WBC champion Vitali and his brother Wladimir, the IBF and WBO champion.
Plans to fight both Ukrainian brothers have fallen through before, but Klitschko appears keen to make the fight happen later this year.
"I told my brother, 'I want to fight Haye', but he said no, he wants to fight him," Klitschko said.
"For him it is personal, but for me I want the title. My brother already has three but I have to clear it with him. I hope he listens to his older brother."
He added: "Always you need motivation and the motivation is to have all the titles in the family.
"Everyone wants to see a unification. Champion against champion. Haye has the choice, one of the brothers Klitschko.
"I'll tell him it's easier to beat me, because I'm older and I don't have as much energy as my brother.
"I keep my fingers crossed that Haye beats Ruiz. Not because I like him, but I want his title and to shut his mouth. Maybe we decide by coins who fights him. Let's hope my brother listens to me. He must always respect old people.
"If someone had told me when I was 20 that I'd be boxing at 38, I wouldn't believe them. But now I am 38 but I think I'm 17, unless I see my grey hair in the mirror."