Sylvester Stallone -- Andre Berto, I Was Kidding ... Stick with Rocky! (VIDEO)

Turns out Andre Berto does have a shot at beating Floyd Mayweather Jr. -- IF he's willing to forgive Sylvester Stallone for saying Floyd would have to drop dead in the ring to lose the title bout.

When we got Sly in downtown L.A. ... he was totally apologetic about the comment he made last week -- telling us, he was "just joking" and Berto is actually a "great fighter."

As for Berto firing back that 'Rocky' was no longer his favorite movie boxer -- pretty sure he was kidding too -- Stallone made a plea for Andre to get himself a little "Rocky magic" before the fight.