Britain's Andy Murray has pulled out of next month's Australian Open because of a pelvic injury.
The three-time Grand Slam champion, 32, was planning to play in his first Grand Slam singles event since Melbourne 12 months ago, when he announced that his career might be done because of injury.
He will also not play for Great Britain in next month's inaugural ATP Cup.
"Unfortunately I've had a setback and as a precaution need to work through that before competing," the Scot said.
"I've worked so hard to get myself into a situation where I can play at the top level and I'm gutted I'm not going to be able to play."
Murray has not been in action since Britain's opening tie at the Davis Cup finals last month because of the pelvic issue.
The former world number one, who underwent hip surgery 11 months ago, did not travel to Miami for his scheduled December training block.
Murray has been on court over the past week, but the injury has not cleared up as quickly as the world number 125 had hoped.
Murray and his team - consisting of coach Jamie Delgado, fitness coach Matt Little and physio Shane Annun - decided he should not rush back for the start of the 2020 season next month.
That has ruled out a remarkable return to the Australian Open in Melbourne where, little under a year ago, Murray broke down in tears during an emotional pre-tournament news conference and admitted he thought an ongoing hip injury would force him to quit.
Murray made a competitive comeback in the singles in August, going on to acquire the Antwerp Open title two months later in just his seventh tournament back.
Since that win over fellow three-time Grand Slam winner Stan Wawrinka, he has only played one more singles match - a laboured three-set victory over little-known Dutchman Tallon Griekspoor at the Davis Cup finals.
Murray will not play a match until February at the earliest, with his first tournament now scheduled to be the Open Sud de France in Montpellier.
Instead of going to Australia he will stay at home and continue hitting on court to build up his fitness.
