Forget Conor McGregor ... UFC fighter Kevin Lee wants to throw down with Kamaru Usman next -- telling TMZ Sports he thinks that scrap would be WAY more challenging than one with The Notorious.
"He might not bring the attention and the money," Lee says ... "But, as a competitor, he'll bring a lot more."
Of course, Lee has been trying to set up a fight with Conor and Khabib Nurmagomedov for the last year ... telling us in the past he'd beat both their asses.
But now, he's saying those fights don't intrigue him as much as a possible scrap with Kamaru does ... saying, "Seeing what he did to Tyron Woodley, that's kind of adding a little bit to me."
Either way, Lee knows fights with any of those three won't go down if he can't get past Rafael dos Anjos in their ESPN+ fight this Saturday night ... which is why he tells us he's laser-focused on that scrap right now.
But, Lee says once he takes care of RDA, he's gunning for Kamaru's belt -- and if Conor wants a shot at him after that ... he can get it then!!!