The former UFC two-weight champion is in training ahead of UFC 264 in Las Vegas in July where he and 'The Diamond' will battle for a third time, with it currently all square at one win one each.
Poirier got the better of McGregor in January when he surprised everyone with a knockout victory in the first round.
The Notorious has been in the gym ever since that loss as he looks to bounce back with a win.
And it seems as though the work is paying off as he looks in great shape.
He posted a selfie on Instagram along with the caption: "Jacked and loaded, what's next?"
The Irishman will be hoping to score another stoppage against Poirier having knocked him out inside one round at UFC 178 back in 2014 when they were just bright-eyed featherweight contenders.
Their second bout was at lightweight and Poirier has tried to tempt McGregor into fighting at welterweight in a Tweet.
But 'The Notorious' simply replied on Twitter, saying: "No."
With the trilogy officially booked, we will finally end the feud and Joe Duffy, who has fought both and beat McGregor early in his career, believes the American will come out on top again.
Duffy told talkSPORT: "I think the fight will go a similar way. I just feel Dustin's octagon time and hunger is a factor. If things aren't going well, he has more ability to adapt in the fight than McGregor has also."