In the main event of UFC Minneapolis two men known for their boxing will square off when Francis Ngannou and former UFC heavyweight champion Junior dos Santos collide. But even though Junior dos Santos is known as a boxer in the UFC, he also happens to be a black belt in Brazilian jiu-jitsu, a fact that Francis Ngannou questioned in a recent interview, expressing his disbelief in the black belt’s authenticity. In an interview with MMA Fighting, dos Santos’s jiu-jitsu coach Yuri Carlton responded to Ngannou’s comments:

“He’s another trash talker looking for attention, trying to impress, or even try to challenge ‘Cigano’,” Carlton said. “Cigano is going there to fight MMA, not jiu-jitsu. (Ngannou) is just another trash talker. If he wants to see Cigano’s jiu-jitsu, he should register to compete in a jiu-jitsu tournament here — well, I mean, I don’t even know if he’s a black belt.”

Stipe Miocic proved that one way to defeat the dangerous knockout artist Francis Ngannou is to take the fight to the mat. Should Junior dos Santos do the same, one would imagine his black belt in jiu-jitsu could come in handy and eventually submit Ngannou, which would be extra sweet after shutting Ngannou up in the process. But Carlton says that the dos Santos camp has nothing to prove:

“I’m not that vain,” Carlton said with a laugh. “Shut him up with a win, no matter how it comes. I just want ‘Cigano’ to win. (Ngannou) is just another guy talking. They all talk. Every fight is the same old story. We’re used to that already.”

UFC Minneapolis takes place this Saturday June 29, with the main card airing live on ESPN at 9:00 PM ET