While most expected UFC heavyweight champion Stipe Miocic to return to the Octagon this fall in search of a division record third title defense, those plans have suddenly been put on hold. 

Miocic (17-2), whose management spoke to MMAFighting.com on Wednesday, isn't willing to discuss his next fight until issues pertaining to his contract are resolved. 

What caused the issue for Miocic, 34, was that during each of his title defenses -- knockouts against Alistair Overeem in 2016 and Junior dos Santos in their April rematch -- it was the defending champion who made the smaller purse. 

The hints that Miocic, who knocked out Fabricio Werdum in May 2016 to win the title, was unhappy came to light in January during an appearance on "The MMA Hour." 

"It definitely should change," Miocic said. "But the fact that [Overeem] made more money than me in my last fight was just kind of a slap in the face.

"[It's] terrible. Things definitely need to be changed. Something's gotta change. It's not really fair."

Miocic's typically quiet and workman-like demeanor hasn't done much for his brand as a marketer. He did, however, go public in June upon the announcement of the August pay-per-view boxing match between Floyd Mayweather and Conor McGregor by pleading for a spot on the undercard against unbeaten boxing champion Anthony Joshua of England. 

One thing Miocic is quickly doing is running out of viable opponents in a thin division. Former champion Cain Velasquez can't get healthy and rising prospect Derrick Lewis recently tasted defeat. There's the dangerous, yet still very raw Francis Ngannou and rumors -- shot down by UFC brass on Wednesday -- that another former champ in Brock Lesnar is considering a comeback.