Facebook CEO Mark Zuckerberg tore his ACL while training for a mixed martial arts competition.
Zuckerberg said he had been training for a fight early next year.
The tech billionaire said he underwent surgery on Friday, but plans to resume training when he heals.
"Tore my ACL sparring and just got out of surgery to replace it. Grateful for the doctors and team taking care of me. I was training for a competitive MMA fight early next year, but now that's delayed a bit," Zuckerberg said. "Still looking forward to doing it after I recover. Thanks to everyone for the love and support."
Zuckerberg shared the news on Instagram, alongside a photo of him in a hospital bed with his leg in a bandage and brace and strapped into a machine.
The Facebook founder competed in his first jiu-jitsu tournament in May, and has been sharing updates online about his MMA training. Last month, he shared a selfie on Instagram of his bruised and cut face, saying "sparring got a little out of hand."
Over the summer, Zuckerberg and X CEO Elon Musk grabbed headlines when they seemingly agreed to a "cage match" faceoff in June, but that appears to have fallen through.
Musk says potential cage bout with Zuckerberg will be held in Italy
The Tesla and SpaceX CEO said he spoke with Italy's prime minister and minister of culture and all have agreed on an "epic location."
