Reigning Wimbledon champion Barbora Krejcikova said Sunday she was pulling out of this month's Australian Open over a back injury.
"Unfortunately, my back injury, which troubled me at the end of last season, is still not fully healed," the world number ten said on X.
"It's really disappointing because I love playing in Melbourne and have such great memories from reaching the quarterfinals last year."
"I'm working hard to get back to full health, and I can't wait to see you on the court soon," Krejcikova added.
The 29-year-old Czech will also sit out this week's Adelaide International.
Krejcikova won the Wimbledon title last year, three years after lifting the French Open trophy.
She has also won seven Grand Slam doubles titles including two at the Australian Open, and three major mixed doubles titles, all at Melbourne.
The Australian Open begins on 12 January.