"This is my club, what do you mean why am I doing this? This is my club, this is my establishment, this is my business," he said.
"The last time I checked, those someones aren't undefeated. It's obvious I know what it takes when it's a fight of this magnitude."
Living up to his "Money" Mayweather persona, the 49-0 all-time great said this was nothing out of the ordinary because his "normal schedule" was to sleep from 5am to about 1.30pm every day.
"Remember for the Pacquiao fight I was out on Friday at the pop-up shop signing autographs and taking pictures with the fans at 2am or 3am," he said.
"The fight is going to be what the fight is going to be, regardless. If I'm at the club or I'm not at the club - I'm a fighter. At the end of the day I can fight. When it's all said and done, I can fight."
Asked what he thought his opponent would be doing at 4am, Mayweather continued the mind games that have been a feature of the build-up to Sunday's encounter.
"I'm pretty sure Conor McGregor is trying to make weight," Mayweather said. "I'm on weight. I'm ready.
"He better be trying to get his weight down ... I know he's over right now. Me? I weigh like 153, 152 (pounds). I don't have to worry about (weight cutting). (I can) eat a Big Mac, eat a Whopper, probably even pizza."
But he didn't stop there, slinging a huge accusation at the Irishman ahead of the 155-pound bout. Mayweather said he'd heard from "a strong source" McGregor was using an IV bag to deal with dehydration.
"From what I'm told - I do my homework - I been hearing a lot about him getting IV bags," he said. "I don't know if it's true, I'm just saying 'rumours' say he's got like seven IV bags, and you know with the Nevada Commission that's illegal, from what I was told. I don't know if it's true, but 'allegedly' he got seven IV bags."
Girl Collection had its official opening on Memorial Day weekend in May, realising Mayweather's long-time ambition to open a strip club.
"Ass, titties, p****, liquor and music will never go out of style," he said. "A regular club you have to keep renovating over and over, whereas with a strip club, you can leave it the same forever. We already know women will never go out of style, especially pretty women.
"This has always been a dream of mine ... and I made it happen."
Mayweather said his total career earnings from boxing would come to $1.1 billion after the McGregor fight, which has already broken the gate record for a boxing event.
"We broke the Pacquaio number," Mayweather said. "Me and Pacquiao did $72 million. Me and McGregor are now over $72 million. Even if it's not sold out, we broke the record.
"We could break the pay-per-view record (too) but there's so much stealing ... a lot of people are stealing fights now."
If not, he's always got his club to fall back on. At any time of the night.
