Remember, the two YouTube superstars clashed at Manchester Arena in England for a 6-round Pay-Per-View boxing match back in August 2018 ... a match that ended in a majority draw.

The fight did impressively well -- even drawing compliments from UFC honcho Dana White -- and leaving many wondering when they would run it back.

But, when we spoke with Logan at Quavo's celebrity charity basketball game on Tuesday in Los Angeles ... he told us some of the big details are being ironed out as we speak.

Paul says the fight will DEFINITELY take place in L.A. and the venue is down to either the Staples Center or The Forum ... two iconic arenas.

As for KSI, Logan says he's confident he'll beat the brakes off his YouTube rival ... telling us, "KSI's a bitch, bro! I mean it!"

Paul also says KSI hasn't been taking his boxing training seriously -- and "he looks like a f*cking meatball right now."

Conversely, Logan says he's in the best shape of his life ... and as you already know, he's fighting all comers in the boxing ring he set up in the backyard of his L.A. home -- including fake Ivan Drago.