Logan Paul insists the dust-up between his brother and Floyd Mayweather was NOT a scripted stunt ... telling TMZ Sports, "I f**king wish that wasn't real."
"I wish it was staged," Logan added ... "That s**t is not funny. It's not fun for anyone."
As we previously reported, Jake Paul took over the media event at Hard Rock Stadium in Miami on Thursday and got right into Floyd's face ... stealing his baseball cap and touching off a violent altercation.
Floyd was PISSED -- chasing after Jake while screaming that he was going to "kill" the YouTube superstar.
We spoke with Logan after the incident and he told us the whole situation is giving him even MORE motivation to flatten Mayweather when they step in the ring on June 6.
"That s**t just got personal by default. It was supposed to be like a cute little press conference ...come together, get people excited for the fight. Not people talking about killing people! What the f**k!?"
We asked Logan if he had a message to Floyd ... and of course, Logan delivered.
"This is gonna be the craziest f**king evening to ever take place in the history of combat sports."
"My message to Floyd is this ... we're gonna get you that hat back, Floyd."
By the way, the Floyd incident was the talk of Hollywood on Thursday -- just ask rapper Rich the Kid, who weighed in on the incident when we spotted him in Beverly Hills.