In a video interview with ESPN commentator Stephen A. Smith published Thursday, McGregor admitted that Poirier wasn't the only thing on his mind before the second fight of their series back in January. McGregor said he was already planning a training camp for a boxing match against Manny Pacquiao that would have taken place after the bout with Poirier.
"I pitied the man," McGregor said. "I was looking past him. I had a Manny Pacquiao camp in place."
McGregor said he "wanted to pat" Poirier on the head "almost" during the lead-up to the fight. There was a mutual respect there, and McGregor said he wanted to give Poirier his due. Poirier ended up winning via second-round TKO.
But McGregor said the admiration and amiable behavior toward Poirier are now gone, leading into the trilogy Saturday night in the main event of UFC 264 at T-Mobile Arena.
"I am a nice guy," McGregor said. "It's just about not translating it into the game. You can't be nice in this business. No matter what. ... In the most ruthless business of all, I am the most ruthless."
McGregor said he left his family behind ahead of his training camp, which he finished in Los Angeles before arriving in Las Vegas on Wednesday. He said he has put his "hard hat" back on and is back at the "building sites," referring to his past job as a plumber in his native Ireland before he made it big as the most bankable star in UFC history.
"It's hard to go face-to-face and want to tear through a man and then hold your son and your daughter and give them a bottle and feed them," McGregor said.
McGregor added that he is now fully focused on MMA, which perhaps he has not been in the past. McGregor had a boxing match in 2017 with Floyd Mayweather, which was one of the biggest pay-per-view events of all time. McGregor said he thinks he will have a rematch with Mayweather "at some stage down the line," but boxing is "not even on the radar at the minute."
There were talks about McGregor fighting Pacquiao in the spring, though the idea was pushed back because of a McGregor injury and his loss to Poirier in January.
With a win over Poirier, McGregor said he will challenge Charles Oliveira for the UFC lightweight title next. UFC president Dana White has already said the winner of this weekend's Poirier-McGregor fight will be next in line for that opportunity.
McGregor said he believes the result has already been decided. He said he "sent electric bolts" down Poirier's body with left hands but didn't swarm for the finish because he was trying to win rounds. That, McGregor said, will not be the case at UFC 264.
"I'm coming in to kill this man," McGregor said. "I'm coming in with vicious intent here. Mortar shots. What else can I say? That's the way it is. ... I'm looking to take this man out cold."