Wladimir Klitschko must defend his IBF heavyweight title against Kubrat Pulev after the Bulgarian was named as mandatory challenger.
Klitschko, who also holds the WBA and WBO belts, extended his lengthy reign with a dominant fifth round stoppage of Alex Leapai last month.
But his IBF title could be at risk unless he faces the unbeaten Pulev in his next fight.
Pulev was handed the mandatory spot after beating Tony Thompson on points last August and is confident he will finally dethrone the 38-year-old champion.
"That's what I call a late birthday gift," said Pulev, who turned 33 last weekend. "I was ringside when Wladimir defended his belts a few weeks ago.
"It was a walk in the park for him against Leapai. When Klitschko meets me inside the ring, I will cause him real problems to say the least. I will show the fans worldwide that Klitschko is no invincible machine and fulfil my dream."
His promoter, Kalle Sauerland said: ''The negotiations with Team Klitschko have already begun. We are excited to present a heavyweight bout in cooperation with K2, which is deserving of its 'Heavyweight World Championship' status.''
The remaining WBC belt has been declared vacant after Vitali Klitschko, Wladimir's older brother, retired earlier this year.
Bermane Stiverne will battle Chris Arreola for the title this Saturday in Los Angeles.