Justin says he's got something NOBODY else who's stood in the Octagon with Khabib has had ... the ability to whoop his ass.
"He's gonna have to fight a stand-up fight with me. He's not gonna be able to take me down."
Standing up with Gaethje -- who was an All-American wrestler in college -- is usually a bad idea 'cause he's known for his powerful hands ... but so was McGregor (and we know how his fight with Khabib turned out).
"Conor was terrified of being taken down."
Justin says he isn't ... and that's why he's the man to hand Khabib his 1st loss.