Deontay Wilder has questioned Anthony Joshua's desire ahead of his rematch with Andy Ruiz Jr.
Wilder, who defends his WBC belt against Luis Ortiz this weekend, has been vocal in his desire to see Ruiz defeat the Brit for a second time next month.
He reckons making a unification bout would be much more straightforward with Ruiz, who shares the same promotional team.
Having failed to negotiate a clash with Joshua to unify the division before his shock June 1 defeat, Wilder has expressed concerns over Joshua's willingness to put his belts on the line as he pointed to "red flags" which question whether he will win his upcoming rematch.
Wilder told Sky Sports : "I prefer Ruiz Jr to win because we're in the same stable. If he wins, we have the opportunity to unify the division. We finally have the opportunity to have one champion, one face, one name.
"If Joshua wins, I don't think that's going to be. He has stated that he has no interest in me.
"I really believe Andy will do it again. A lot of red flags have alerted me. If that same mindset and momentum go into the second fight, Ruiz Jr will win easily.
"I want a unification. The heavyweight division is too small to have so many champions. I understand that in the lower weight classes. But the heavyweight division is all about the big boys, all about the power. This is a special division.
"They say: 'wherever the heavyweight division goes, so does the sport of boxing'.
"I believe that, and that's why we need one champion.
"If I have another fighter that is willing to put his belt on the line with mine, then that's what I want."
