A dispute outside of the octagon might be threatening one of the UFC’s biggest upcoming fights. Conor McGregor has suggested on social media that he no longer plans to face Dustin Poirier in their highly anticipated trilogy bout, which is scheduled for July 10.

The latest dust-up between the lightweights stems from a charity donation that McGregor agreed to make ahead of facing off in the main event of UFC 257. McGregor said he would donate $500,000 to Poirier's charity, The Good Fight Foundation. On Sunday, Poirier said McGregor’s camp stopped responding to his foundation after he knocked out McGregor in their Jan. 24 fight.

McGregor responded to Poirier’s tweet, claiming that no donation had been made because he was waiting for information about how the money would be used. The exchange between the fighters became heated, and McGregor indicated that would replace Poirier with another opponent for the scheduled fight at UFC 264 this summer.

“The fight is off btw,” McGregor tweeted at Poirier. “I’m going to fight someone else on the 10th. Good luck on your old contract kid.”

The two continued to tweet at each other. Poirier sent McGregor a gif of his knockout from a few months ago. McGregor posted a picture of Poirer on the ground from UFC 178 in 2014 when the Irish superstar defeated Poirier in their first meeting.

It’s not yet known if the verbal spat will actually force the fight to be called off. Poirier officially signed a contract to fight McGregor on July 10, ESPN reported earlier this month. McGregor reportedly verbally agreed to the bout several weeks ago.

This wouldn’t be the first time that McGregor posted an intention about his UFC career that didn’t come to fruition. McGregor has announced his retirement on multiple occasions, only to return to the octagon not long afterward. In September, McGregor announced on Twitter that he would face Manny Pacquiao in a boxing match, which never happened.

McGregor is the strongest draw in UFC history. His fight with Poirier in January helped make UFC 257 one of the best-selling pay-per-views of all time.

Knocked out: Conor McGregor
Knocked out: Conor McGregor GETTY IMAGES NORTH AMERICA / Harry How