McGregor (22-5), 32, of Dublin, Ireland, has flown out to Las Vegas this week to continue his training camp as he steps up his final preparations for the fight.
It promises to be one of the biggest pay-per-view bouts in the history of mixed martial arts, with both fighters occupying two of the top spots in the premier lightweight division at some point over the past couple of years.
Both men have had their fair share of support, with a number of others currently undecided over who will emerge victorious.
Oliveira has become the latest UFC fighter to try his luck at picking out a winner – and he has tipped McGregor to come out on top against Poirier.
Oliveira’s pick for McGregor vs Poirier III
The 31-year-old praised both fighters, but believes that McGregor’s punching power will give him the edge over his opponent.
Oliveira also says that he would be more than happy to fight the winner as he ultimately doesn’t care about who he faces next, let it be McGregor or anyone else.
He told TMZ: “Conor McGregor by knockout.
“I’m the champion. For me, McGregor or Poirier are the same.
“I’m the champion. I’m ready to fight, I’m the champion.”
Likewise, St-Pierre also agrees with Oliveira, as he believes that McGregor’s experience in rematches could pay dividends.
“I think McGregor is very good in rematches and I think he’s going to have the victory,” St-Pierre said to Tristar Gym’s YouTube channel.
“I think he’s probably going to win in the second round by knockout.”
But St-Pierre’s longtime coach Firas Zahabi expects the outcome to be almost exactly the same as their second encounter.
Poirier defeated McGregor by second-round knockout in the main event of UFC 257 on Fight Island.
Zahabi countered: “My official pick was 50-50 odds. I think it could go either way, but because GSP picked McGregor, I’ve got to pick Poirier.
“I’m going to make a case for Poirier right now. I think at 155 [pounds], McGregor’s power is maybe not exactly what it used to be, and he’s got to do five rounds.
“I think Poirier showed in fight number two, he’s smart enough to take McGregor in the later rounds. And you know what? In round one, he took a big left and he took it well.
“I think psychologically now Poirier’s a bit more ready to take that left hand. And he’s more aware about it.”
He added: “I think this is an incredibly difficult fight.
“Fifty-fifty, but if Georges picked McGregor, I’ve got to pick Poirier, and I think Poirier’s going to take him in round three, and he’s going to do the same thing he did before.
“He’s going to kick the leg, he’s going to injure McGregor a little bit on the leg, and then he’s going to put the hands on him. It’s going to be a trench war and Poirier’s gonna put him away.”