McGregor's return to the octagon didn't go quite as well as he had hoped. The 32-year-old was knocked out by Poirier in only two rounds.
Fans of the two fighters had to wait almost seven years from the original fight between two, McGregor was victorious in the inaugural featherweight bout.
The Diamond's victory now puts both men level with one victory each. UFC boss Dana White has revealed plans for the third instalment to take place this summer.
The Notorious one is not wasting any time in preparing for this bout as he has recently uploaded a gym picture on his Instagram.
In the photo, McGregor can be seen looking jacked as he flexes his chest and biceps.
The announcement there would be a rubber match between the two came as no surprise to fans.
Immediately after their bout in January, McGregor made it known he wanted to have a definitive end to the series with Poirier.
Dana White when talking to ESPN about the match said:
"If you look at Conor, if you look at the way he fought, the leg kicks he was eating, the stance he was in, he was completely overlooking Dustin Poirier.
"I'm not taking anything away from Poirier, but when you pull in on a superyacht and you're living the life that Conor lives, you need to be hungry and you need to take every guy seriously.
"It doesn't matter how you beat Dustin Poirier the first time, that's not the same guy you are going to be facing and obviously Dustin Poirier is training like it's the most important fight of his life."
McGregor is one of the UFC's greatest fighter and a real blockbuster name in the MMA world.
The Notorious One holds the number one spot with Khabib for the most PPV buys in UFC history, an astonishing 2.4 million buys for UFC 229.
McGregor unsurprisingly appears another five times on the top ten list for most UFC PPV buys.
Dana White will be hoping the pull of this final instalment of the two will make the top ten too, as the UFC president is certain it'll be a good match.
Dana White said: "There were a lot of things lined up there (McGregor/Poirier's last fight) for an upset.
"I guess the good part is, for the trilogy McGregor is hungrier than he's ever been - he wants this fight back, he wants this fight badly. So it will be a fun third fight."News Now - Sport News