Mir, who has a clean history of drug use throughout his mixed martial arts career, was knocked out by "Super Samoan" in the first round with a devastating overhand right.
The former two-time champion released a statement on social media shortly after the news of his potential anti-doping violation and claims he never used any performance enhancing drugs.
Mir also declared his innocence on the Phone Booth Fighting podcast with Richard Hunter earlier today. According to the 36-year-old, he passed two random drug tests conducted by the United States Anti-Doping Agency but flagged for anabolic steroid metabolites - oral turinabol - in the scheduled test for his fight with Hunt.
Mir says there are a load of potential reasons for his failed drug test, including kangaroo meat in Australia (h/t Roy Billington of Bloody Elbow), but insists that he didn't willingly take any illegal substances.
"I couldn't tell you a single restaurant I remember eating at. I even remember calling James and saying 'do you remember where we ate?' I had to write down all of the places we went. And even if I could figure it out; let's say someone could document where I went. You're telling me USADA are gonna go down, and, on my behalf, try to test all the different meats to see if, well, you know, kanagaroos are wild and this guy wanted to beef em' up so he bought something that was very abudnant - in the study that I did - oral turinabol could be bought in powdered form.
You put it on the food and you bulk up your livestock, and you could sell it into the stores because now you get more bang for your buck. An animal that takes two years to reach maturity, you know, muscle weight, now in four months he's bigger than he's ever gonna be and you slaughter him. It's a common practice. I don't know, I'm not pointing the finger any where, I'm just saying there's so many loopholes for me to sit there and go 'where did it come from?' Hell man, I don't know, I really don't. All I know is that I didn't willingly take anything."
Mir was originally expected to feature as an analyst for tomorrow's UFC Fight Night: Dos Santos vs. Rothwell event, but will no longer be covering the show.