Paul Felder has seen a lot while working for the UFC, but he's never seen anything like what happened this past weekend.

On Saturday, Felder was on the call for UFC Vegas 121, headlined by a five-round bantamweight fight between Raul Rosas Jr. and Raoni Barcelos that ended up being one of the scariest moments in UFC history.

In the fifth round, Barcelos appeared to suffer some sort of medical episode while Rosas was working on a takedown, going unconscious despite seemingly not suffering any major blow to cause it. Rosas stepped off from Barcelos, who was quickly attended to by the on-site medical team, but the Brazilian fighter remained unconscious for several minutes.

Eventually, Barcelos was removed on a stretcher and taken to a local hospital. A few hours later, Barcelos' coach provided an update saying that Barcelos is conscious, lucid, and mobile, and it seems like he will ultimately be OK. That's great news, especially as, while sitting cageside when it all happened, Felder was not sure that would be the case.

“His neck was all clinched up, and he was unconscious,†Felder said on the Believe You Me podcast. “And it looked like he was — I thought he had a heart attack, off the bat. Then they came in, and they checked his pulse, which was terrifying to see. I have never seen somebody that was KO'd, where they come in and the first thing they did, the doctor put his fingers right on Raoni's pulse. I was like, ‘Oh, this is really bad.'

“He was just not getting up, and then I'm thinking, is it a stroke? Is it a heart attack? But if they weren't doing CPR and his pulse was at least there and present, and he's breathing, probably not a heart attack. …

“That was by far the scariest thing I've had — I've seen some nasty knockouts, guys out for a while, but they come to. To see somebody where the doctors are checking your pulse, it just kind of really puts it in perspective, too, what this sport is at its roots.â€

There are still no details about what happened with Barcelos, though that information will likely come out in the coming days. But for Felder, unless all the tests say that what happened was some terrible fluke, he hopes Barcelos won't press his luck and continue fighting after this.

“They should give Raoni, like, another five [hundred thousand] on top of [the Fight of the Night bonus] for whatever, because that might be it for him,†Felder said. “I think, no matter what, I'd love to see him retire. Hey, your body gave out on you to some degree. Unless it comes back that it was just some fluke thing, but to get rushed to the trauma center, and you're 39? …

“There's still just so many questions out there on what really went down, and if they even know. That's the scarier part: what if they can't even pinpoint what exactly caused that? You've got to be done with combat sports. And if so, what a career this guy's had. At 39, what a resurgence he's had.

“Thoughts and prayers to his family. I really hope he's OK. It was really sad to see.â€

Update. Raoni Barcelos' coach shares medical update after scary UFC Vegas 121 fight ending.

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I've been watching MMA since 2002, and Saturday night was easily one of the scariest moments of my fandom. There have only been a few times in 24 years that I've thought, “Oh no, this is it,†and the Raoni Barcelos situation was one of them. Super happy he's OK (or, at least, not as bad as it could be) , and like Felder, I hope I never see him fight again.

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