Last month, Jeffrey Guan made his PGA Tour debut at the Procore Championship.

He missed the cut, but just competing in the event was a massive accomplishment for the 20-year-old Australian pro.

Then, a week later, everything changed.

Playing in a pro-am during regional qualifying for the NSW Open in Australia, Guan suffered a fracture to his left cheekbone and eye socket after he was struck by a stray ball.

There have been few details about what happened, but on Thursday Guan took to Instagram to explain the incident, the aftermath and his recovery.

He also made a promise.

Guan said on the 3rd hole he and his playing partner both hit drives up the right side of the fairway. His partner hit first, and then Guan drove up and played his ball. After he hit, he turned and walked back toward the cart to put his club in his bag, and that’s when he was struck with an incoming ball.

“The instant ringing and pain rushed to my head, and I dropped to the ground,” Guan wrote on Instagram. “Voices sounded pretty muffled, and the next thing I knew, I was in an ambulance being transported to a hospital with skin patches containing high does of Fentanyl.”

Guan was taken to Moruya Hospital then airlifted to Canberra for treatment from an eye specialist. He had his first surgery that night — “I was in unbearable pain, and anxiety about my future was swirling,” he wrote — and a day later had a second procedure at Sydney Eye Hospital.

For the next two weeks, Guan was in intensive care. He said he completely lost vision in his left eye.

“I couldn’t do much,” he wrote. “Sleeping was difficult, let alone walking or eating. Any activity that required energy meant I was in excruciating pain.”

Three weeks after the accident, Guan learned the pressure in his eye had finally decreased toward normal levels, and his eye was more stable.

“That was the first piece of positive news,” he wrote.

Still, doctors told him he had several fractures around his eye socket, and his recovery would take at least six months to a year.

Two years ago, Guan won the Junior Players Championship and played in the Junior Presidents Cup. In 2022-23 he played well enough on the Challenger PGA Tour of Australasia to earn a promotion to the Australasian PGA Tour, and in November 2023, after finishing 9th at the Asia-Pacific Amateur Championship — a tournament that awards the winner an invite to the Masters — he turned pro and joined the Australasian PGA Tour. He had a top-five finish at the Victorian PGA Championship in just his second start, and he added three top 10s since.

Guan earned a sponsor’s exemption into the Procore in Napa, Calif., but not long after his PGA Tour debut he was stressing about his future from a hospital bed.

Guan said those nights were the most difficult, and he said the situation made him depressed and angry and affected his emotional and mental health.

“Fortunately, I have been lucky enough to have a huge support group around me, and I can’t thank all of them enough for the support I have received in recent weeks,” he wrote. “I wouldn’t be where I am right now without all the encouragement and assistance I have received. As a kid, I have always had a lot of perseverance and persistence. I will continue to work hard and do my best to achieve my dream. These four weeks have been the toughest of my life, but I am stronger mentally and will be ready to conquer any obstacle in the future.”

As for that promise?

Guan offered four words: “I will be back.”

The Australian Sports Foundation launched an online fundraiser for Guan. You can donate here.