UFC president Dana White has warned Conor McGregor he will be stripped of his featherweight title unless he quickly moves to clarify his future fighting plans.
Irish superstar McGregor stunned the world of mixed martial arts by announcing his retirement from the sport with a brief tweet on Tuesday.
The UFC acted quickly by announcing it had pulled him from the main event of its blockbuster UFC 200 card on July 9 after he refused to travel to Las Vegas later this week to promote the landmark card.
McGregor was scheduled to face Nate Diaz in a rematch of their March welterweight fight, which the American won via second-round submission.
Also on the card, former featherweight champion Jose Aldo is scheduled to meet Frankie Edgar for an interim featherweight title.
The plan was for the winner to then face McGregor later this year but White has warned the Irishman that Aldo and Edgar will fight for the real belt unless he clarifies his position.
"That's the thing: Conor needs to clear up this whole retirement thing and clear it up fast because if he's retired, then at UFC 200 Jose Aldo and Frankie Edgar are fighting for the vacant title then," White said, during an appearance on Wednesday's episode of The Herd on Fox Sports 1.
When asked if he believed McGregor has truly retired from MMA, White said: "I do not."
White said he believes McGregor will fight in the next year before adding the mixed-martial arts superstar could still feature at UFC 200.
"If he called me after this interview we'd probably still do it," White said. "The problem is this - you have to be here to promote your fight and you have to shoot this commercial.
"We're spending $10m in promotion for UFC 200 and all that money is in motion. You can't do this. I don't care who you are or how big you are, you can't do this."
As things stand, the UFC are left scrambling to find a main event for a card they announced a year ago. The rest of the card had been met with a mixed reaction from fans before McGregor was pulled and being forced to withdraw the sport's biggest pay-per-view star does nothing to further the UFC's cause.
Diaz is without an opponent but appears far from certain to stay in the main event slot without McGregor.
Prior to his win over McGregor at UFC 196 in March, Diaz - who was called up to fight on late notice after an injury to lightweight champion Rafael dos Anjos - had never headlined a UFC pay-per-view event.
The Stockton native was soundly beaten by Dos Anjos at the end of 2014, and he suffered unanimous-decision defeats to Dong Hyun Kim and Rory MacDonald in his only two fights at welterweight, making a shot against welterweight champion Robbie Lawler hard to justify.
McGregor is a superstar who transcends the sport and - aside from probably Ronda Rousey - is the only active fighter the UFC would allow to headline one of the biggest nights in its history without a world title on the line.
The most obvious candidate to step into the breach may be pound-for-pound number one Jon Jones.
The former light-heavyweight king makes his long-awaited return following a 16-month layoff against Ovince Saint Preux at UFC 197 this Saturday.
Jones was originally supposed to face Daniel Cormier but the reigning light-heavyweight champion was forced to pull out of the bout due to injury.
Providing Jones comes through against Saint Preux unscathed, his rematch with Cormier would emerge as the most natural candidate to fill the void at UFC 200. That is a prospect which would excite Jones.
"Absolutely, I would totally step in to UFC 200 and fill in that main event or co-main event slot," Jones told media on Wednesday.
Though Jones may stand to benefit from McGregor's apparent rift with the UFC, he was quick to offer support to the Irishman.
"Hats off to him for standing up for what he believes is right," Jones added "At the end of the day, business is business, and the guy obviously has respect for himself and his talents.
"Fights like this will help fighters in the future. So, I respect his balls. I respect his willingness to fight for what is right."