Bad news for Conor McGregor ... Justin Gaethje will NOT agree to fight the Irishman before he gets his title shot with Khabib Nurmagomedov, this according to Justin's manager.
Conor has been trying to bait Gaethje into a big-time showdown on Fight Island in July -- calling out Justin on social media and threatening to kill him.
But, we spoke with Gaethje's rep, Ali Abdelaziz, who tells us the trash talk strategy just won't work -- Justin's already focusing on fighting Khabib next .