Georges St-Pierre's long-time coach Firas Zahabi has sensationally accused Conor McGregor of being "jealous" of rival Dustin Poirier, claiming the former UFC lightweight champion "suffers from narcissism."  

Last week, McGregor, 33, suffered a second consecutive defeat for the first time in his career after breaking his leg at UFC 264 on Saturday night in Las Vegas. 

However, "Notorious" refused to concede defeat, as the former two-weight champion continued to target Poirier's wife and family. 

"I was boxing the bleedin’ head off him, kicking the bleedin’ leg off him," McGregor said in his post-fight interview.

“This is not over. If I have to take it outside, let's take it outside.”

The Irishman added: “Your wife is in my DMs. Hey baby, hit me back up on chat later on. We’ll be at the after party, the Wynn nightclub, baby. [Inaudible], you little h--. F--- him.”

McGregor last week also described Poirier as a "corpse. A dead body that's going to get his ass whooped and took out on a stretcher."

He added: "I'm throwing kill shots now. Every shot I have thrown in this camp is a kill shot. That's it. I'm going to kill this man."

That didn't go down well with Zahabi, who then went on a rant about McGregor and criticised the Irish MMA fighter for bringing the sport into disrepute.  

He told the Tristar Gym YouTube channel: “I was really grossed out. I don’t know how you guys can be fans of this man.

"I respect him as a fighter. I respect his skills – I can’t deny that.

"But the way he behaved at the press conference was just horrible.”

Zahabi also attributed a portion of the blame to McGregor's inner circle as he believes he is surrounded by a bunch of yes-men and women who pander to everything he says.

“If Conor McGregor has one true friend in this world - maybe he’s just surrounded by people who just want his prestige and money and they just want what they can get from him,” Zahabi said.

“But if he has a single true friend in this world, that true friend is going to take him behind closed doors and tell him, ‘Look, the way you’re behaving – it’s stupid. You’re making yourself look bad. You’re embarrassing us, your family, your friends.’

"It’s just a humiliating way for a true martial artist, a warrior to behave.

“He’s going after kids now. Now, if that was anybody else, if that was a guy on a prelim card, we would all be like, ‘Kick this guy off the roster. Kick this guy out of the UFC. No, no, no.’

"But because it’s Conor McGregor, you can’t say that. It’s Conor McGregor – he’s the poster boy. He’s the one who sells all the tickets. No – there’s no pass for that.”

While Zahabi condemned McGregor's "disgusting" behaviour both before and after the fight, he had nothing but praise for "The Diamond", adding: “McGregor is so down. He’s so angry and jealous of Poirier.

""He will say and do anything to try and insult Poirier, try to take away this moment off Poirier.

"Listen, Poirier has beaten you. He’s a better fighter than you. He will be remembered as a better fighter than you...

“Whatever beef you have there, you can’t take it and start threatening to kill each other and then start threatening each other’s children, team members and whatnot. That’s just animal behaviour.

"Then to say what he said about Poirier’s wife – it’s disgusting.”

Zahabi, who has also previously coached the likes of Vitor Belfort and Robert Whittaker, also believes that the 33-year-old's ego has affected his performances inside the Octagon, which he feels has contributed to his recent poor run of form. 

McGregor has now lost three of his last four fights in the UFC, having been stripped of his lightweight title due to inactivity. 

He added: “I think McGregor suffers from narcissism, heavily, heavily narcissistic, and unfortunately for him, he can’t see that he’s at fault.

"That’s why he needs a true friend or family member to step in and kind of sober him up a little bit because honestly, all he did was embarrass himself. You’ll never see a fighter behave like this.

“He’s the only guy that even if he loses, he can’t take it. He can’t look in the mirror and say, ‘You know what? That wasn’t my fight. It didn’t go my way. I lost. Here’s what I have to do to improve. This is how I better myself.’

"No, no, no – in his mind, ‘It was a freak accident. There was no check. You were going to get a beating in the second round.’

"It’s just nonsense. Pure nonsense. Not only has his skills as a fighter dipped, but also his character.”

Read more: Paul Felder slams 'disgusting' Conor McGregor's post-fight antics after loss at UFC 264