MELBOURNE, Australia (AP) — Rafael Nadal withdrew from the Australian Open with an injury a week before the season's first major was due to start after playing just one tournament in his comeback from 12 months on the sidelines.

Nadal said he had concerns over his surgically repaired hip after needing a medical timeout in the third set of his Brisbane International quarterfinal loss to Jordan Thompson on Friday.

The 22-time major winner initially said it seemed like more of a muscular problem than the tendon issue that caused him so much pain this time last year.

But he posted on social media Sunday that scans after he arrived in Melbourne revealed a small tear in the muscle and he was flying back to Spain for treatment.

"Hi all, during my last match in Brisbane I had a small problem on a muscle that as you know made me worried," Nadal said on X, formerly Twitter. "Once I got to Melbourne I have had the chance to make an MRI and I have micro tear on a muscle, not in the same part where I had the injury and that’s good news.

"Right now I am not ready to compete at the maximum level. I’m flying back to Spain to see my doctor, get some treatment and rest."

Nadal’s latest injury setback comes after being away from the court for almost a year and having surgery on his troublesome hip in June. The former top-ranked player also had a history of knee and foot issues that many thought would threaten his ability to remain on the tour for as long as he has.

But Nadal's latest comeback looked promising as he won his first two competitive matches in a year before losing to Thompson. He wasted three match points in the second set with uncharacteristic errors in his quarterfinal before losing in three.

"A lot of things can be happening in a body like my body after a year without playing tennis," he said after the loss to Thompson. "So hopefully it is just that, just a muscle that is supercharged. If that’s the thing, perfect."

The 37-year-old Spaniard opened the tournament with straight-sets wins over Dominic Thiem and Jason Kubler but was pushed for 3 hours and 25 minutes by Thompson in what was his third match in four nights.

Nadal was playing on a wild card in Brisbane but had a protected ranking for the Australian Open that would have given him a start in the 128-player main draw.

Since arriving in Australia, Nadal had appeared to be lowering expectations of what he could achieve during the tour's swing through the country and that his focus was to be fit for the clay court season and the French Open in May, where he has won a record 14 times.

"I have worked very hard during the year for this comeback and as I always mentioned my goal is to be at my best level in 3 months," he said. "Within the sad news for me for not being able to play in front of the amazing Melbourne crowds, this is not very bad news and we all remain positive with the evolution for the season.

"I really wanted to play here in Australia and I have had the chance to play a few matches that made me very happy and positive."

The Australian Open is due to start Jan. 14 at Melbourne Park, with No. 1-ranked Novak Djokovic − who has a record 24 Grand Slam singles titles − favorite to win.