Rafael Nadal abandoned his planned ATP Tour comeback at the Indian Wells Masters on Wednesday, saying he was not ready for the demands of tournament tennis on the eve of his opening match in California.

The Spanish icon's bombshell decision came four days after the 37-year-old lost a Las Vegas exhibition to compatriot and world number two Carlos Alcaraz.

Nadal missed almost all of the 2023 season with abdominal and other injuries and has played only the Brisbane International this season, where he suffered a flare-up of a hip injury.

The 22-time Grand Slam champion had been due to open at Indian Wells on Thursday against Canada's former Wimbledon finalist Milos Raonic.

"It is with great sadness that I have to withdraw from this amazing tournament at Indian Wells," Nadal said in a statement.

"I have been working hard ... but I don't find myself ready to play at the highest level at such an important event.

"It is not an easy decision, it's a tough one as a matter of fact but I can't lie to myself and lie to the thousands of fans.

"I will miss you all and I am sure the tournament will be a great success."

Indian Wells tournament director Tommy Haas expressed disappointment at Nadal's withdrawal.

"We wish him continued healing and hope he can be back in action again soon," Haas said. "He is one of the all-time fan favorites here, and we hope to see him back in Indian Wells again in the future."

On Sunday, Nadal had given an encouraging performance in his Las Vegas clash with Alcaraz.

After suffering a muscle tear in Brisbane in January, Nadal withdrew from the Australian Open, the first Grand Slam of the season.

Dogged by injuries 

He then scrapped plans to return to action at the Qatar Open in February, saying he was "not ready to compete."

Injuries have been a recurring theme of Nadal's record-breaking career, a by-product of his all-action, brutal-hitting style that has led to serious knee, wrist and foot problems.

During his career, Nadal dominated the French Open, where he won 14 of his majors, his first arriving just days after his 19th birthday in 2005, his last in 2022 making him the event's oldest champion.

He is a four-time champion at the US Open, won Wimbledon in 2008 and 2010, and is a two-time winner at the Australian Open -- with 13 years spanning his first triumph at Melbourne Park in 2009 and his second in 2022.

Wednesday's withdrawal at Indian Wells will stoke inevitable speculation about the Spaniard's retirement date.

In January however Nadal declined to confirm that 2024 will be his last season, backing away from earlier hints he may quit the sport this year.

"The problem about saying that's going to be my last season is I can't predict what's going on 100 percent in the future," he said in Brisbane in January.

"You never know what's going on, you know? I can't predict how I'm going to be in the next six months. I can't predict if my body will allow me to enjoy tennis as much as I enjoyed the past 20 years."

He admitted though that he had contemplated retirement during his lengthy injury absence from the sport last year.

"Of course I was asking myself that (about retirement), but at some point I decided to keep going. I had the determination to keep going," Nadal said.