In a post on his X platform, formerly known as Twitter, Elon Musk revealed that he will be receiving an MRI on his neck and upper back on Monday, and the 52-year-old may ultimately need to get surgery.

In his post, he said this week he will find out if he will require surgery ahead of his proposed cage fight with rival billionaire and founder of Meta Platforms Inc, Mark Zuckerberg. Previously Musk had said that he “might need an operation to strengthen the titanium plate holding my C5/C6 vertebrae together.”

Musk’s health is of intense interest to investors given the crucial nature of his roles as chief executive officer of both Tesla Inc, and Space Exploration Technologies Corp., as well as the owner of the microblogging site X, formerly known as Twitter. Musk has commented that he has suffered from “mega back pain,” ever since he engaged in a bout with a sumo wrestler.

Musk had mentioned the injury in a post which challenged Russian President Vladimir Putin to “single combat” over the war in Ukraine last year.

Musk has been stirring controversy with talk of a potential cage match with Mark Zuckerberg, as competition between the two CEOs has grown over Meta’s introduction of Threads, a rival social media platform which mimics many of the features of Musk’s social media platform, X. Although Threads saw decent initial traction, more recently it has seen active daily users fall by 82 percent.

On Threads on Sunday, Zuckerberg posted that he had suggested August 26th as a potential date for the cage-match, however he has not yet heard back from Musk. He wrote, “I’m ready today. Not holding my breath.”