Conor McGregor could miss UFC 219 after 'unacceptable' behaviour

McGregor storms cage and confronts ref (0:45)

Conor McGregor jumps into the octagon to celebrate with SBG Ireland teammate Charlie Ward after his Bellator 187 victory and goes after the referee. (0:45)

Conor McGregor could miss out on headlining UFC 219 after a commissioner branded his behaviour at Friday's Bellator event in Dublin "unacceptable."

The lightweight champion stormed the cage to celebrate a victory for team-mate Charlie Ward and reacted angrily when referee Mark Goddard attempted to eject him -- sparking scenes of chaos as McGregor tried to traverse gathering security to confront Goddard a second time.

The 29-year-old was expected to be the main event at UFC 219 on Dec. 30 but president of the Association of Boxing Commissions and Combative Sports Mike Mazzulli revealed that a UFC executive has confirmed to him that the incident in Dublin has put paid to the possibility.

Mazzulli said on The MMA Hour: "They basically said to me that it's completely unacceptable in their eyes and that they will be doing something.

"They did inform me that he was set to be on the December 30 card and now he will not be on it. So I do commend the UFC to some extent for doing that. On the other hand, I will be looking at it and speaking to my attorneys upon returning to the United States to see if I have any action."

McGregor's coach John Kavanagh defended his fighter's actions, telling The 6 O'Clock Show: "Charlie is one of Conor's very close friends and he's coming off two pretty devastating losses.

"He was a little bit over emotional there, but you sort of understand when you know his and Charlie's relationship over the last number of years."

McGregor was last in action in a boxing ring back in August -- suffering a 10th-round stoppage at the hands of the legendary Floyd Mayweather in Las Vegas.