Brock Lesnar isn’t the only fighter to have reportedly been at odds with the UFC over the new ESPN+ pay-per-view deal.

Conor McGregor is the UFC’s top-drawing star. UFC 229 topped the promotion’s record for PPV buys at 2.4 million. Headlining that card was a lightweight title bout between McGregor and champion Khabib Nurmagomedov. “The Eagle” won that bout via fourth-round submission. While Nurmagomedov is expected to return in September, McGregor and the UFC haven’t worked out the next bout.

ESPN’s Ariel Helwani reports that a roadblock in McGregor’s return has to do with the UFC’s new PPV model through ESPN+:

“A sticking point between the two sides has been the new pay-per-view landscape after ESPN+ became the UFC’s exclusive pay-per-view provider in the United States. McGregor is the biggest pay-per-view draw in MMA history, so he will be the most affected fighter on the roster since the new deal went into effect in April. Thus far, the two sides haven’t come to terms on a deal, sources say.”

UFC president Dana White was supposed to meet McGregor in Miami to discuss the “Notorious” one’s fighting future, but that never materialized. White said the two rescheduled the meeting for Los Angeles. McGregor and the UFC had discussed a potential July return, but the former two-division champion didn’t want to take a co-main event spot unless he had ownership stake in the promotion.

Lesnar, a former UFC heavyweight champion and current WWE star, was initially thought to have been the next title challenger for Daniel Cormier. White revealed that Lesnar told him he has retired from mixed martial arts. Dave Meltzer reported that Lesnar also had issues with the UFC’s ESPN+ PPV deal.