NEW YORK (AP) — Elon Musk says he may need to get surgery before a proposed “cage match” with Mark Zuckerberg.

The two tech billionaires seemingly agreed to an in-person face-off in late June. It’s unclear if a physical fight will actually end up happening, but Musk and Zuckerberg have continued to fuel interest in the potential match through online jabs at one another — most recently on Sunday, when Musk said the fight would be live-streamed on his social media site X, formerly known as Twitter.

Musk added that the fight’s proceeds would go to a charity for veterans. On his Threads social media account, Zuckerberg responded: “Shouldn’t we use a more reliable platform that can actually raise money for charity?” In a follow-up post, the CEO of Facebook’s parent company Meta said he wasn’t “holding his breath” for a fight.

“I’m ready today. I suggested Aug 26 when he first challenged, but he hasn’t confirmed,” wrote Zuckerberg, who is actually trained in mixed martial arts and posted about completing his first jiu jitsu tournament earlier this year. “I love this sport and will continue competing with people who train no matter what happens here.”

Earlier Sunday, Musk said was training for the fight by lifting weights. He later addressed the timing of the fight — noting the date “is still in flux” due to a scheduled MRI and the potential of surgery.

“I’m getting an MRI of my neck & upper back tomorrow,” Musk wrote Sunday night. “May require surgery before the fight can happen. Will know this week.”

Talk of an in-person fight all started in June, when Musk, who owns X, responded to a tweet about Meta preparing to release a new Twitter rival called Threads. He took a dig about the world becoming “exclusively under Zuck’s thumb with no other options” — but then one Twitter user jokingly warned Musk of Zuckerberg’s jiu jitsu training.

“I’m up for a cage match if he is lol,” Musk wrote. After Zuckerberg appeared to agree to the proposal, Musk proposed the Vegas Octagon.

Whether or not Musk and Zuckerberg actually make it to the Las Vegas ring has yet to be seen — especially as Musk often tweets about action prematurely or without following through. But, even if their cage match agreement is all a joke, the banter gained attention. An endless chain of memes and posts to “choose your fighter” sprung up in response.

The Associated Press reached out to Meta, X and Ultimate Fighting Championship, which owns the Octagon, for statements Monday morning.