Joshua and Ruiz collide in Saudi Arabia on Saturday with the Briton looking to avenge the defeat he suffered in June.
The Mexican and the Briton meet in Saudi Arabia six months after their first fight, with Ruiz looking to defend the WBA, WBO and IBF belts.
Saudi Arabia hosting Anthony Joshua and Andy Ruiz Jr for the "Clash in the Dunes" is just the latest in a long tradition of sportswashing tyranny.
The bizarre incident unfolded after Pulev stopped Romania's Bogdan Dinu in seven rounds on Saturday night.
The unification clash is now being negotiated.
Anthony Joshua could earn as much as $50 million per fight if he switches to MMA.
The British heavyweight champion could face a rematch with Wladimir Klitschko.
The fighter's mother is Nigerian and he reportedly tried to join the country's 2008 Olympic team.
Fury says he needs to deal with his "medical treatment and recovery."
American Dominic Breazeale will fight Anthony Joshua for the IBF world championship on June 25.
Deontay Wilder, Bermane Stiverne and Luis Ortiz could be contenders for the fight.