In the press conference itself, McGregor continued to show the bravado that made this fight a big deal in the first place, saying the lightweight gloves Mayweather agreed to means he'll beat the boxer in two rounds, down from the four rounds he's been predicting for weeks.
"I am a multiple-time, multiple-weight, free-fighting world champion", he says. "He's beaten. He will not take the ferociousness that I come with".
It's half-fight, half-spectacle, a bout that matches a UFC star who has never boxed against a masterful ring technician with a record of 49-0. He's a fighter. It's going to be blood, sweat and tears on Saturday.
With the fight now being contested with eight-ounce gloves - previously 10-ounce - the Irishman added that Mayweather made a big mistake by proposing the change in glove size. "I come out and bang people right away".
"When this one is done I will have 20 seconds where I relish in victory and then I will be thinking who is next?" We told you why - now just go take your money. And it's not going to be easy, Conor.More news: Ramsey Abbey College 'extremely proud' of students
What will happen is McGregor approaching Mayweather cautiously, looking more so last than to win? "I am skilled in combat, a lot more than him".
"I've been with my team my whole life, they know every shot I throw, they know my moods, they know everything".
Earlier yesterday, Mayweather had taunted McGregor over his fitness, telling the USA website FightHype that he believed his opponent would struggle to make the 154-pound limit for Saturday's bout. I don't want to do this, I want to go home. "We have prepared for 12, three minute rounds of nonstop pace and I will go forward, put the pressure on him and break this old man, trust me". Mayweather has the best defence world and he will be hard to hit.
"This is a lot more subdued, a lot more business like", McGregor began.
The two fighters got together for the final pre-fight press conference to further hype a fight built on hype.
Oh, and he also doesn't lack confidence, which is no small thing when facing odds as daunting as McGregor's chances against Mayweather. Today, he said the undefeated boxer's gambling habits and bad decisions had ultimately brought them together.
"He needs to shut his mouth", McGregor said. That's the game I come from. All I do is fight, I want to get in there and fight.