Floyd Mayweather's Dad 'Pretty Sure' Floyd Will Fight Manny Pacquiao Again

Floyd Mayweather's father tells TMZ Sports he's "pretty sure" his son is down for the rematch with Manny Pacquiao ... and he's warning PacMan that TBE will "kick his ass" again!!!

"I'm pretty sure that they gonna fight," Floyd Sr. told us on the way into the Beverly Wilshire hotel ... "If Pacquiao says he wants to fight, I'm pretty sure they're gonna fight again."

Floyd Sr. would know ... he's pretty tight with his son. In fact, Floyd Jr. gave a heartfelt speech at his father's Nevada Boxing Hall of Fame induction earlier this month.

And, Fun Fact -- Floyd Sr. was his son's trainer for the first Pacquiao fight back in 2015, a fight Floyd easily won.

Speaking of Manny, he called out Floyd on social media after he beat up Keith Thurman back in July ... telling Floyd, "If you want to be relevant again #MayPac2."

Manny looked VERY impressive in his victory over Thurman -- but Floyd Sr. says he ain't worried about the 40-year-old Filipino superstar.

"Man, my son will kick his ass the 2nd, 3rd, 4th, 5th [time]!!!"

Only one way to find out ...