"This is a serious issue, this is not a light issue," Marnell added. "This isn't, 'We smacked each other in the face in a hotel lobby the week of a fight.' This is the night of the event, and it needs to stay inside that field of combat. There are serious regulations and statutes about what took place, and the consequences have to match the actions."
He said the commission planned to hear the matter in November.
Speaking before McGregor was cited, UFC president Dana White told TMZ he felt Nurmagomedov should be fined $250,000 and suspended for four to six months.
"They took his whole purse right now and they're talking about keeping his purse," White said. "You should not be able to keep his whole purse."
McGregor was initially cast as a victim because of the disgusting he way he was set upon by three men who climbed inside the cage. But a closer inspection showed him swinging first while he straddled the top of the cage alongside Nurmagomedov's cousin, Abubakar.
KHABIB KICK 'NO BIG DEAL'
It came after McGregor's coach John Kavanagh described the Russian's decision to climb out of the Octagon and launch a flying kick after his win at UFC 229 as "no big deal".
After forcing McGregor to tap midway through the fourth round of their lightweight title battle, Nurmagomedov launched at McGregor cornerman Dillon Danis and could now face a suspension which could force the UFC to strip him of his title.
But Kavanagh hopes any sanctions aren't too punitive. "I hope (NSAC) is lenient on (Nurmagomedov)," said Kavanagh, during an appearance on the Joe Rogan Experience.
"Not just so we can get a rematch. I just love watching him fight. I can stretch myself to understand his reaction."
In his post-fight press conference, Nurmagomedov indicated months of personal taunting by McGregor about his family and religion had gone too far.
There were suggestions on the night Danis had also touched a nerve with his post-fight trash talk, but Kavanagh denied it.
"(Danis) actually didn't say anything," revealed Kavanagh. "I was standing beside Dillon. I didn't see what he did but I could hear. He didn't say anything. When I watched it back I could see him beckon (Nurmagomedov) on. It's just stupid end of fight stuff. But it didn't justify that level of response.
"Maybe there was something else in the build up. Dillon is a little bit of trouble online. But, like I said, it wasn't that big of a deal to me what Khabib did. It just really wasn't."
HIT FROM BEHIND WAS 'CRIMINAL'
Kavanagh did, however, have a problem with Zubaira Tukhugov climbing into the Octagon and hitting McGregor from behind.
"If Khabib had done that isolated, I didn't think it was a big deal," Kavanagh said. "He didn't really hit Dillon. There was a bit of pushing and pulling. Who cares?
"But a man coming up, a trained fighter with bare knuckles, hitting a guy who's tired, who's taken some rounds and taking some shots, there has to be ramifications for that. An example has to be made ... It's criminal. It's assault."
Marnell said NSAC was also investigating Tukhugov. "We're taking a really hard look at that gentleman," he told ESPN. "We know exactly who he is and where he is. I have to let the Attorney-General determine -- is that trespassing, disturbing the peace? That was a serious action and it deserves a serious consequence."
Fresh footage showed Kavanagh was the first to jump to McGregor's defence. "Jumping in is what any friend would do but getting there in double time wearing flip flops was a challenge," he tweeted.
White immediately pulled Tukhugov from a scheduled fight against Artem Lobov at a UFC Fight Night in New Brunswick on October 28 in the wake of his attack on McGregor. He said Tukhugov, who has fought four times in the UFC, would never appear in the Octagon again.
The 27-year-old has shown no remorse for his actions, bragging about his involvement online.
"I slapped him as promised. I promised to make him answer for his words and I did," he said in a video posted to social media.
"Tell everyone who thinks I was hit, where? Where? Nothing. Just this cop pushed me away ... was not even close."
Police in Las Vegas have confirmed there were no arrests after the post-fight melee which followed McGregor's defeat.
"Las Vegas Metropolitan Police Department officers assisted with breaking up several small fights that took place after Saturday night's UFC main event in Las Vegas. After all parties were separated, no one involved wished to press charges and no arrests occurred," a statement read.
McGregor was making his return to mixed martial arts after a two-year hiatus in an event which was billed as the biggest in the UFC's history.
The duo's camps clashed in Brooklyn in April in an incident which saw McGregor charged by police after he threw a handcart that smashed the window of a bus containing several fighters, including Nurmagomedov.