Anthony Joshua and Deontay Wilder have tentatively agreed on a deal to fight on 9 March in Saudi Arabia.
The fight would follow the historic undisputed title showdown between Tyson Fury and Oleksandr Usyk, which also takes place in Saudi on 17 February, where all four major belts will be on the line for the first time since Lennox Lewis in 1999.
Joshua and Wilder will hope to secure a match against the winner later in 2024 but face major hurdles before then.
The heavyweight rivals will share a spectacular card two days before Christmas in Riyadh with Joshua taking on Otto Wallin, while Wilder will be in action against former WBO heavyweight champion Joseph Parker.
