Jermell Charlo says he's down to fight Conor McGregor for his next big scrap ... and tells TMZ Sports it can be boxing OR MMA!!!
"We always on standby," Charlo says ... "Especially for an MMA fight. Why not?!"
Of course ... Conor's next opponent IS up in the air after he got mauled by Khabib in October -- and Charlo's also lookin' for a fight after he takes on Tony Harrison Saturday night.
So, could it happen?