Rafael Nadal has pulled out of Indian Wells 24 hours before his first-round match with Milos Raonic on Friday.
Nadal, 37, made his long-awaited return at January's Brisbane International, after almost a year out with injury.
However, the Spaniard sustained a hip injury at the tournament which ruled him out of the Australian Open.
Nadal played an exhibition match against Carlos Alcaraz on Sunday, but said he is not yet ready "to play at the highest level".
"It is with great sadness that I have to withdraw from this amazing tournament," the 22-time Grand Slam winner wrote on Instagram.
"Everyone knows how much I love this place and how much I love to play here at Indian Wells. That's also one of the reasons why I came very early to the desert to practice and try to get ready."
In May, after being forced to miss the French Open for the first time in 19 years, Nadal said 2024 would "probably" be the final year of his career.
Last month, the former world number one said he was unsure of how many tournaments he would be able to compete in before retiring, but added that it was "not going to be many".
"I have been working hard and practicing and you all know I took a test this weekend but I don't find myself ready to play at the highest level at such an important event," Nadal, a three-time winner at Indian Wells, said on Thursday.
"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."
Nadal's next tournament is likely to be on his favoured clay surface at next month's Monte Carlo Masters, where he is an 11-time champion.
BBC