Alexander Povetkin (34-1, 24 KOs) is expecting to become the next opponent for IBF, IBO, WBA, WBO world champion Anthony Joshua (21-0, 20 KOs).
Povetkin, an Olympic gold medal winner and a former world champion, is the mandatory challenger under the WBA and WBO.
The WBA recently ordered the two fighters to negotiate a deal or risk the possibility of heading to a purse bid. They have until May 6th.
Joshua's promoter, Eddie Hearn, anticipated this possibility, and placed the Russian boxer on undercard of Joshua's event last month at the Principality Stadium in Cardiff, Wales.
Povetkin scored a brutal fifth round knockout over Olympic bronze medal winner David Price, while Joshua appeared in the main event and won a twelve round unanimous decision over Joseph Parker to unify his four belts.
There is some talk of a fight between Joshua and WBC champion Deontay Wilder - but the two sides are very far apart on the financial terms.
Andrei Ryabinsky, who promotes Povetkin, believes the contest with Joshua will happen next.
"I believe that Joshua will follow and cooperate with the rules of the sanctioning bodies for the titles that he holds," Ryabinsky exclusively told Sky Sports.
"I think every fighter has to fight the best to prove that he is the best. I see no reason why Joshua would not want to fight Povetkin as his next opponent. We have started discussing the fight. [Joshua's promoter] Eddie Hearn is a very respectable promoter, we consider him our partner, and we hope that we can have a pleasant and efficient negotiations process."
Povetkin's promoter has no problem with doing the fight at any major venue in the UK, Russia or even the United States.
"We are happy to make the fight in England as both fighters have a lot of fans in England, there are many Russians that live in England and many who will come to England for the fight," Ryabinsky said.
"Yes, of course, it is possible [to fight Joshua in Russia]. [The Luzhniki Stadium] has been recently renovated, it's a legendary stadium, it has the capacity for a fight of this magnitude. Doing the fight in the USA is also an option."