Conor McGregor out of UFC 303 headliner against Michael Chandler due to undisclosed injury

Conor McGregor, long the face of the UFC, is injured and out of the upcoming pay-per-view event June 29 in Las Vegas that he was scheduled to headline.

Organization President Dana White announced the change Thursday night on X, saying light heavyweight champion Alex Pereira will face top-ranked challenger Jiri Prochazka in UFC 303.

UFC 303 International Fight Week June 29th <a href="https://t.co/P47PSsKcg0">pic.twitter.com/P47PSsKcg0</a>

McGregor was scheduled to fight Michael Chandler, the sixth-ranked lightweight challenger, but the first indication that bout was in trouble was when his news conference June 3 in Dublin was abruptly canceled. No immediate explanation was provided.

Losing McGregor, who hasn't competed inside the octagon in three years, is quite a blow to the UFC. At 35, he is past his prime, but remains a strong attraction for gate and pay-per-view sales.

The UFC is at a crossroads, with stars such as McGregor, Jon Jones and Amanda Nunes either near the end of their careers or having already retired. There is a group of younger fighters still building their fan bases that the UFC is counting on to lead the next generation.