LAS VEGAS — Tears rolling down his cheeks and dripping onto his dress shirt, his voice catching and at times so broken it was inaudible, Jon Jones, arguably the baddest man mixed martial arts has ever known, faced the media Thursday morning as an emotional mess.

This was hours after receiving word from the United States Anti-Doping Agency that he tested positive for performance-enhancing drugs. That cost him his headlining spot in Saturday’s UFC 200, while potentially bringing a two-year ban from a sport and derailing a comeback story from recreational substance abuse and legal issues.

“Ah, man,” Jones said, before pausing for more tears. “… I just want to apologize to everybody, sincerely. I really don’t know what to say, I’m really sorry that this is happening.”

Jones maintained his innocence by denying that he knowingly took a banned substance. He argued that whatever triggered the positive test came without his knowledge. His agent, Malki Kawa, said they will fight the finding and are having the B sample tested Thursday, with results possibly coming as soon as Thursday night.

The UFC has officially pulled Jones light heavyweight title fight with Daniel Cormier off the card and even a clean B sample may not change that. Regardless, such a B sample bailout is unlikely, Kawa noted.

“The chances of that happening is very slim but we are holding out hope,” Kawa said.

Jones claimed he couldn’t pronounce what he got popped for and would attempt to retrace his steps and see what he was taking through training camp to identify the problem. Kawa is well schooled on the details but refused to provide any, at this point sticking with a broad sweeping defense.

“He didn’t cheat at all,” Kawa said. “He didn’t at least try to do anything wrong.”

That distinction will do little to placate fans who already purchased Saturday’s historic card expecting to see Jones and Cormier renew their rivalry. And it will do little to ease frustrations from Cormier, who lost a huge payday and opportunity, not to mention the UFC itself, which trusted Jones was clean, sober and organized enough to not blow up its high-profile, signature event.

Jones should be afforded full due process and the appeals process of USADA, which engineers UFC drug testing. His explanation for what may have happened, however, speaks to his typically reckless behavior. He said he doesn’t immediately know, and didn’t record every substance or supplement he took during training camp because he didn’t believe it was needed.

“I never even thought I was in a gray area that I would need to write down what I was taking,” Jones said. ” … I wouldn’t cheat.”

Fair enough in theory, completely negligent in practice. This is big business and such a casual approach to what enters his body was foolhardy at best, self-sabotaging at worst. Jones’ camp said he’s been tested randomly eight times this year, with the last, a June 16 test, coming up positive. He is also further tested for recreational drugs as part of his probation from a hit-and-run accident in New Mexico.

“There’s a few things that have nothing to do with performance that I’ve tried,” Jones said. ” … Right now I’m just going through and thinking about every single thing I’ve taken before the fight.”

This is an absurd position to put himself in. An athlete under that kind of microscope, with tens of millions to lose and a career, not to mention the public’s trust, hanging in the balance, can’t simply ignore the possible dangers of whatever he puts into his body.

Jones has the resources, both financially and professionally among his top-tier team, to guard against this. If Jones can afford a crisis management public relations professional (who apparently gets so much work she stood in front of the media and declared, “I assume you all know who I am.”) he can certainly have someone monitor this.

There are no excuses.

And that’s if – if – this was accidental and not part of a purposeful attempt to skirt the rules. The UFC has taken a zero-tolerance stance against PEDs and for good reason. This isn’t someone swimming or running faster than an opponent; this is a fight where serious injuries and even death can occur.

Jones (22-1) is as good of a mixed martial artist as the sport has ever seen, a gifted athlete who typically overwhelms opponents and energized the UFC with his performances. His one loss came all the way back in 2009 via a controversial disqualification.

He has fought just once in the past 18 months however, having continued personal troubles. Through his career there have been positive tests for a metabolite of cocaine, a car accident and later the hit-and-run that put him on probation for 18 months. The UFC stripped him of his title in 2015 and suspended him for six months. He has spent much of his career feuding with UFC management and fans.

This was supposed to be his redemption, a crowing comeback following a long-awaited return victory in April. Instead it’s one more knock against him, performance-enhancing drugs this time, but another pay-per-view card ruined regardless.

“I want to first start by apologizing to all the fans, all the fans who came out to support me for UFC 200,” Jones said through tears. “Obviously the UFC [and owners Frank and Lorenzo] Fertitta … not being able to perform. I know there’s been a lot to go into this event. All the staff of the UFC. Daniel Cormier … I want to apologize to him.

“The fight meant a lot to him,” Jones continued. “The fight meant a lot to me. And the fight is not happening.”

To his credit, he wanted to speak publicly as soon as possible, a hastily called Thursday morning news conference, so he could put himself out in front of fans. That took courage. It doesn’t change reality.

“Being labeled as someone who would ever cheat hurts me more than anything I’ve ever been through in my career,” Jones said.

The news conference was raw and at times uncomfortable to watch, a star laid bare. Jones, 28, had to leave the podium for a stretch and retreat to a back hallway here at MGM to collect his emotions. At other times he openly wept, wiped his face, fought through long pauses and tried to hold it together.

He promised it wouldn’t derail his stated sobriety, believing he is strong enough to survive the test. He also began to face the reality that a two-year ban from the sport was a possibility.

“If I do have to sit for two years, I’ll definitely be back,” he said.

There wasn’t much more to say.

“At the end of the day, I’m a fighter,” Jones said. “I’m a fighter. And even though I may seem broken up here, I’m not broken. I’m just really upset.

“I just have to keep going,” he said, wiping his eyes.

Just outside the news conference, MGM Grand workers were scrambling to pull down promotional banners featuring Jon Jones as UFC 200 main event.

They were trying to wipe away any sign he was ever here.