The WBO has named Oleksandr Usyk as the mandatory challenger for the winner of Anthony Joshua's heavyweight-title rematch with Andy Ruiz Jr.
Usyk has been given priority over Dillian Whyte, with the WBO pointing to the Ukrainian's "exceptional amateur career" and "unblemished professional record" (16-0), which saw him become undisputed champion at cruiserweight.
Ruiz stunned Joshua earlier this month to take his WBO, IBF and WBA belts, and the pair are set to meet again in November or December at an as-yet-unspecified location.
The WBO said in its official ruling: "The foregoing accomplishments of Mr Usyk awarded him WBO Super Champion status recognition whereby he's entitled to certain rights and privileges, including mandatory challenger designation in an immediate higher or lower weight division."
Usyk unified all four belts in the cruiserweight division by defeating Murat Gassiev in July 2018 and went on to defend them against Tony Bellew four months later.
However, the Ukrainian was forced to pull out of his scheduled heavyweight debut against Carlos Takam in May due to injury.
Whyte (25-1) has won nine consecutive bouts since losing to Joshua in 2015, but his commitment to fight Oscar Rivas in London in July was held against him in the ruling, as he was deemed unavailable to fulfil the mandatory position.
Although the WBO decision is 'final', Whyte has 14 days to appeal the ruling.
Joshua suffered a huge upset as he lost his unbeaten record on his US debut earlier this month, with Ruiz claiming a stunning seventh-round knockout in New York.