In the days before their title bout, Diaz lobbed numerous allegations of steroid abuse at St-Pierre. "I believe [St-Pierre] is on plenty of steroids, and I don't think they test around here, either," Diaz proclaimed on Canada's Sportsnet Radio.
"I doubt I'll be tested. I don't care what they're saying or marketing to the media -- and if so, he's probably got a bottle of p--s in his pocket. I doubt they're standing over him making sure he's not on steroids."
Both St-Pierre and Diaz ultimately passed post-fight drug tests, however with the accusation of steroid abuse out there, St-Pierre invited more stringent Olympic-style drug testing to MMA. Now, with the next defense of his belt set for November, St-Pierre is making good on that promise.
"One reporter asked me if I would be willing to be tested. I said yes, I would be willing to be tested with VADA," St-Pierre told MMAFighting.com. "I believe that VADA is the best anti-doping agency in the world. And I'm willing to be tested. You cannot be against [it]."
St-Pierre's UFC 167 dance partner, Johny Hendricks, wasted little time agreeing to St-Pierre's terms, and now the two are slated to undergo VADA testing prior to their winter welterweight clash, all on St-Pierre's dime.
"I'm ready to pay [for our testing] myself, because I'm the champion," St-Pierre said. "All from my purse, I paid for the tests because I'm the champion. That's why I'm ready, I'm ready to do it. That's a point I want to make.
"I wouldn't mind doing it for the rest of my career," he continued. "Of course it sucks. They can come anytime, you have to give your address and then [VADA representatives come] in the morning. It sucks. But it's my sport and it could be an inconvenience of my job, I'll do it no problem."
Ask St-Pierre if Diaz's remarks led him down this current path, and the 32-year-old champ will flatly deny it. He insists Diaz's chatter was always just background noise, and he paid it no mind.
Nonetheless, Hendricks has already been far more measured in his criticism of St-Pierre than the Canadian's former opponent, and it's clear St-Pierre appreciates it.
"The talking never hurt nobody. It comes in one ear and goes out the other," St-Pierre concluded. "I don't care. I don't mind. Johny doesn't need to speak. I know he's a gentleman, and he's a great, skillful athlete. His performances speak for themselves.
"A lot of people accuse me [of taking PEDs]. For me, when they accuse me, I take that as a compliment. I believe they compliment my athleticism. I want to prove also that it's possible to be champion without using drugs, and I know VADA is the most professional, it is the best for that."