Wladimir Klitschko is likely to take on Russian heavyweight Alexander Povetkin early next year.
The World Boxing Association has declared that the WBA 'super champion' must face the 'regular champion' Povetkin before February 26.
"We are very excited that Povetkin will be Klitschko's next opponent," said Povetkin's promoter Kalle Sauerland.
"We consider Wladimir Klitschko to be a great champion but we also consider Alexander Povetkin to be a very serious challenger. [This] will turn out to be a real treat for boxing fans all over the world."
Povetkin set up the Klitschko bout with a victory over former champion Ruslan Chagaev in August last year.
Klitschko, who holds the WBA, IBF, WBO and IBO heavyweight titles, defeated Poland's Mariusz Wach on points in his last outing.