Conor McGregor may be in serious trouble. The reigning UFC lightweight champion made a surprise appearance at the end of UFC 223 media day on Thursday and allegedly picked up a guardrail before hurling it at a passenger van with fighters on board.

As fighters wrapped up media day festivities and were preparing to leave, McGregor and his team seemed to appear out of nowhere trying to enter the fighters' van as before it headed back to the hotel, according to MMAFighting's Ariel Helwani. When he was unsuccessful in getting in, McGregor appeared to pick up a guardrail and throw it at the van, shattering the glass and injuring at least one person on board.

According to Helwani, lightweight fighter Michael Chiesa was cut during the chaos and is being treated at the arena. It is unknown if it will affect his scheduled main card bout with Anthony Pettis on Saturday night. Following the madness in Brooklyn, Chiesa's coach Rick Little described the events to MMA Junkie

"Conor went bananas and put a beating on the van that we were in looking for Khabib," Little said. "A million security guards had to restrain him. Mike's cut up now. He's got marks on him, for sure. I don't think too serious. Everything happened so fast, it was just like we got jumped."

While Little didn't believe the cuts to be serious, which may in fact be the case, Chiesa was still taken to the hospital to undergo further evaluation

While this is all bizarre, our shock levels shouldn't be all that high. As McGregor has rose to fame in combat sports, his flare for the dramatics has grown along with him. Who could forget the drink throwing melee involving McGregor prior to his UFC 202 rematch with Nate Diaz, which led to a suspension from the Nevada State Athletic Commission after several in attendance were injured. His antics were also on full display ahead of his superfight with Floyd Mayweather in the boxing ring last summer. 

As part of the aftermath, the New York State Athletic Commission released a brief statement to MMA Fighting on the matter. 

"The incident that occurred today at the Barclay's Center was unacceptable and has no place in New York State sports.

Multiple published reports, including photos and video, evidently show Mr. McGregor and members of his entourage engaged in destructive, abhorrent and illegal behavior and endangered the safety of those around them. It is our understanding that local law enforcement is involved and is actively responding to the matter.

At least one fighter scheduled to fight on Saturday was purportedly injured in the incident. Medical staff will assess any injured fighters to determine whether they are fit to compete as scheduled.

The Commission has commenced a dialogue with the UFC and Barclay's Center management in response to the incident. All parties are working together to ensure that appropriate protocols are in place for the protection of the fighters and the fans at UFC 223 and at tomorrow's weigh-in. The Commission is also conferring with the associated security staffs to ensure that heightened safeguards are implemented prior to the weigh-in and the event.

Mr. McGregor is not licensed by the New York State Athletic Commission."

While the finishing portion of the statement regarding McGregor's licensing in the state of New York has little bearing in this matter, it's still noteworthy the commission was quick to react to the lightweight champion's actions on Thursday.