The Game is already callin' a Soulja Boy knockout if a fight with Aaron Carter actually goes down ... telling TMZ Sports, the boxing match would be a "sloppy slugfest!!!"
If you missed it ... Soulja and AC have been going back and forth after the singer called him out for a celeb boxing match ... with Draco saying he'd "beat the candy out his pockets!"
We learned there's an actual offer on the table for this to pop off .