Conor McGregor scored the most important – and most impressive – victory of his UFC career Saturday night when he caught former featherweight champion Jose Aldo with a left hand 13 seconds into the fight, knocking him out. The win should legitimize McGregor to even his most ardent doubters, but chatter about Aldo threatens to taint the win.

Rumors are circulating that Aldo may have been using steroids for much of his career, and was off them for the McGregor fight. UFC commentator Joe Rogan, who pulls no punches on his podcast, discussed the rumors at some length. His guest. UFC fighter Brendan Schaub, also noted that Aldo looked “soft” compared to other fights.

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“He's never failed a test, but who knows. You're bats**t crazy if you don't think Jose Aldo's body looked different. You're bats**t crazy if you think he's gonna fight the same. Also, his camp, I think, is 1-7, 0-8 since this drug testing came out. So you're talking about a different fighter, man. For me, that's a huge X-factor," Schaub said.

Rogan said that Aldo has called the police on people who tried to test him during training camp before UFC 189, and eventually provided a sample, but “tripped and spilled his piss.”

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Twitter users noticed Aldo’s different body as well.

Should Aldo be discovered to have used PEDs in the past, that could serve to deflate McGregor’s momentum coming off that win. Even if the current rumors take hold, it does a disservice to McGregor, clearly one of the most talented MMA fighters in the world, as he tries to become the UFC’s biggest draw.

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