Conor McGregor is in.
However, he also said that he wants the fight to happen at AT&T Stadium in Arlington, Texas, home of the Dallas Cowboys.
"Jerry Jones is a friend and the stadium can hold our crowd," McGregor said in his tweet. "I will be ready for Texas and Texas will be ready for my fans! Then Manny."
McGregor has expressed interest in facing Manny Pacquiao in the boxing ring and even stated on social media that part of the reason he wants to face Poirier is because Poirier is a southpaw -- like Pacquiao -- and known as one of the better boxers in MMA.
McGregor holds an 0-1 record in professional boxing. That lone fight was, of course, one of the most lucrative fights in combat sports history against Floyd Mayweather in 2017. McGregor lost via TKO in the 10th round.
UFC would need to either sign off on McGregor's participation in boxing or be part of the promotion, as the company was in 2017 when McGregor fought Mayweather.
Poirier responded to McGregor on Twitter: "Close to home for me on my birthday weekend! What weight?"
McGregor has agreed to the fight only verbally. There is no bout agreement yet, sources said.
Poirier said Wednesday on Ariel Helwani's MMA Show that UFC has yet to reach out to him about the fight.
McGregor hasn't fought since his 40-second TKO victory over Donald Cerrone in January. Before that fight, he said he was hoping to fight three times in 2020. However, the coronavirus pandemic and failed negotiations with UFC have stalled his return, leading to a public feud of sorts with UFC president Dana White.
Last week, McGregor promised that he would donate $500,000 to Poirier's Good Fight Foundation charity, as he promised to do when the pair tried to set up a charity sparring match two weeks ago.