Here's the deal ... Carter inked a deal to fight October 2 in Miami -- but doesn't yet have an opponent. He even made a video, looking for a dance partner.
Welp, seems he might've found one in the 3x All-Star aka "Nails" ... who responded with a video message for AC.
"Lenny Dykstra here, nails. Guess what? I'm going back in the ring October 2nd in Miami with Aaron Carter. I'm gonna f****** take this mother f****** apart piece by piece, okay? October 2nd. In Miami. Don't miss it. Me and Aaron Carter. Mono e mono. Let's get it on, nails back in action."
We're told Celeb Boxing is trying currently trying to lock Dykstra in ... which would make the fight official.