Donald "Cowboy" Cerrone says Conor McGregor is refusing to fight him unless their bout headlines a UFC card.
"Conor won't fight unless it's a main event," Cerrone told ESPN's Brett Okamoto.
"I don't know if it's an ego thing or a status thing for him. I don't give a shit. I'll fight anyone, anywhere, and I stand by that all the time. I guess he's a prima donna and only takes main event spots, I don't know."
McGregor and Cerrone have expressed mutual interest in a fight but haven't yet been able to finalize an agreement.
Cerrone, who has fought more times in the UFC than anyone else in the promotion's history, said he intends to be in the Octagon again by July 6, regardless of whether the opponent is McGregor.
"We were all waiting on Conor for April, and he said he wasn't ready," Cerrone said. "I don't know how in one breath you can say, 'I'll fight anyone, anytime, anywhere,' and the next one say, 'I'm not ready for that one.'
"I'm more annoyed that he went radio silent after putting it out. I get it, you want to stay relevant by putting it out there, but then you can't go radio silent. Sack up, b----. Sign the f------ paper."
McGregor has only one UFC tilt to his credit in the last two-plus years, which he lost to Khabib Nurmagomedov for the lightweight title in October.