"He may not like to admit it, but he's my fan," Cormier tells TMZ Sports ... "He enjoys watching me compete. He does!"

DC says there's not a doubt in his mind JJ will be tuning in when he fights Stipe Miocic at UFC 226 on Saturday because, despite all the trash talk over the years ... "he likes watching me."

Cormier has a secret, too ... and it has to do with Jon Jones -- admitting he'll use JJ when he's playing the UFC video game because his character is "the best guy in the game."

At the end of the day, Cormier hates Jones -- but he hates losing in video games even more!

Cormier says he's also aware that he's a heavy underdog going into the Stipe fight ... but has some advice for gamblers out there -- the smart money is on DC, and he explains why!