Brendan Schaub fired back at Nate Diaz with a fiery promo.

Last week on his podcast, Schaub emotionally opened up about his friend Shane Carwin, a former UFC interim champion, and his financial and physical struggles following an open letter written by Carwin as part of the UFC antitrust lawsuit. Schaub was in tears as he was giving more insight to the situation. Hours later, Diaz reacted by taking a personal shot at Schaub.

This week on The Schaub Show, the former UFC heavyweight, turned comedian and podcaster, delivered his response.

“This is just internet gossip,” Schaub said. “This is getting him trending, he doesn’t have a lot going on, didn’t get paid for the Masvidal fight, probably doesn’t know what he’s going to do next. Conor, he’s probably waiting on that. Conor’s tied up with the TV [rights] deal, so he’s probably banking on that. He fought Masvidal, lost to Jake Paul — that’s a big blow to his ego. So I guess he needs to do this to stay current.

“I retired 15 years ago, man. That being said, that’s social media. This isn’t real, because here’s what’s real: I will f*ck you up. That’s real. I’m not asking for this. I don’t want to f*ck him up, I’m not trying to f*ck him up. End of the day, if he walked in here right now, ... only one of us is going to walk out unscathed, and it’s me. Every f*cking day of the week, 365 days a year, I will snap his f*cking neck.”

Diaz is looking for his next fight after defeating Jorge Masvidal in a boxing match earlier this year. Diaz filed a lawsuit against Fanmio, the promoter of the event, saying he’s allegedly owed $9 million.

As far as Schaub goes, he respects what Diaz has done as a fighter, but in his eyes, that wouldn’t matter in this situation.

“He’s had some great fights, tough dude, I don’t give a f*ck,” Schaub explained. “I’m 245 pounds, trained black belt, top-10 UFC heavyweight in the world at one point, I’m not out of shape. I’m a f*cking beast when it comes down to it. I know, I tell jokes, I do crazy shit, I made some mistakes, ‘Oh, he got knocked out by Nogueira, ... silly dude, I get all that. At the end of the day, the way this works, I’m not a civilian like the rest of his goons around him. I’m not this fake gangster, I don’t go looking for fights. I know I’m tough.

“I don’t have to get on Twitter and blast it out, and prove it every day because I’m insecure, because of whatever shit he has going on with his childhood trauma. I don’t have to do that. At the end of the day, I will twist your f*cking neck off. ...

“The difference between you and I is if your brother — Shane’s a brother to me — but if your actual f*cking brother came out and started getting emotional, or if you started getting emotional about your brother’s issues with CTE and fighting and all this shit — because we know he has his issues — I would support you,” Schaub continues. “Even though you’ve been a dick to me the entire time.

“That’s what I do. That’s what men do, bud. I wouldn’t bash you, and this whole narrative, this entire narrative, ‘Oh, f*ck the man,’ bud, you’ve been paid more than 99 percent of the fighters. Cut the bullshit. You’re no different than Colby Covington with his MAGA shit. It’s all fake, bud. You’re not fooling anybody. I’ve seen how the sausage is made. You’re not tough to me. I know tough guys. Tough guys don’t get on the internet and tweet at another grown f*cking man, who’d beat the shit out of him when they’re crying, or getting emotional because their friend of 20 f*cking years is having major issues, suicidal thoughts. That’s p*ssy.”

Schaub ended up retiring from the sport in 2014 following a first-round TKO loss to Travis Browne at UFC 181, a moment that led to friend and UFC color commentator Joe Rogan having a real moment where he urged Schaub to retire.

The fighter is still inside of Schaub, as he says, and while he’s not seeking a fight, if Diaz wants one, Schaub will be happy to oblige.

“What are you going to do Nate? What are you going to do? You going to volume punch me, motherf*cker?” Schaub said. “That’s what you’re going to do? What are you going to do, out grapple me? In what f*cking sense? What world are you living in? This is the real world.

“Now, if you’re doing this because you fancy yourself [some] fisticuffs, if you fancy yourself [and] you want to actually grapple me, I’m not hard to get a hold of. Pull the f*ck up. And you can show up with all your boys, do all that stuff, but what a real man will do is pull up one-on-one. I don’t have a posse, I don’t need one, bud. I’ll drop my kid off at f*cking practice, roll over, twist your f*cking neck off, and then pick him up just in time unscathed with a Diet Coke. And that’s how this goes for the rest of your f*cking life, bud.”

Of course, Diaz was made aware of Schaub’s comments, and reacted to them on Twitter — using one of Schaub’s infamous quotes in the process.

“I think you’d be surprised,” Diaz wrote.