Last updated on .From the section Boxing

Oleksandr Usyk stopped Tony Bellew in the eighth round to retain all four cruiserweight belts in November

Ukrainian Oleksandr Usyk has been named mandatory challenger for the winner of Anthony Joshua's heavyweight-title rematch with Andy Ruiz Jr by the WBO.

Usyk, 32, the former undisputed world cruiserweight champion, pulled out of his heavyweight debut against Carlos Takam in May because of injury.

Ruiz, 29, stunned Joshua to win the IBF, WBA and WBO titles on 1 June and is under contract to take a rematch.

The rematch has been mooted for later this year, possibly in New York.

Usyk was the first boxer to hold all four world titles at cruiserweight when he won the World Boxing Super Series tournament.

The 2012 Olympic champion's final bout in the lighter division came in November when he knocked out Briton Tony Bellew - a seventh successive world title victory.

He is unbeaten in 16 professional fights, with 12 knock-out wins.

The winner of the proposed rematch between Joshua and Ruiz will hold three of the four major world titles, with WBC champion Deontay Wilder in possession of the other.

Usyk is now positioned to face Joshua or Ruiz but the title holder could also vacate the WBO belt should they wish to pursue another avenue.