Rivera is a stud -- he's the #5 ranked bantamweight who once had a crazy 20-fight win streak with victories over guys like UFC Hall of Famer Urijah Faber.

Now, Rivera is trying to claw his way back into a title shot and knows he's probably gotta go through Cody for a chance to face champ T.J. Dillashaw.

"You know, what's on my list is Cody," Jimmie says ... "If he finally answers my tweets or gets his balls from Urijah Faber's purse, we can make a fight happen early next year and I can whoop his ass and give him his 3rd loss and end his career just I like did Faber."

Rivera fought -- and beat -- Faber back in 2016, the 2nd to last fight of Faber's career.

Now, Garbrandt trains with Faber -- the two are very close friends.