Michael Johnson Wants UFC to Strip Conor McGregor's Belt

UFC lightweight Michael Johnson has a message for the UFC -- vacate Conor McGregor's belt already!!

"Who knows when he's gonna come back?" Johnson told TMZ Sports. "As I look at the division, I don't see a champion right now."

FYI -- McGregor hasn't defended his 155-pound title since winning it way back in November. Clearly, Johnson's not convinced Conor will return to the octagon after making BANK boxing Mayweather.

As for Johnson ... he's fighting an undefeated Justin Gaethje in the main event of Friday night's "The Ultimate Fighter" finale -- looking to move one step closer to Conor's gold with a W.

Gaethje's a scary dude -- seriously, go watch his highlights -- but MJ says he's shook ... and promises to wreck the UFC newcomer for talkin' smack.