Kei Nishikori has been forced to pull out of the Australian Open later this month as he battles with a wrist injury.
The three-time quarter-finalist in Melbourne has not played since August, and although he is making good progress, the event at the Rod Laver Arena has come too soon for him.
The 29-year-old says he was desperate to play in the first Grand Slam event of 2018 but is not yet ready to compete over five sets.
"It hurts that I will have to miss it," he said. "My rehab is going well but I am just not ready 100%"
The news is another setback for tournament organisers, who are already sweating over whether star names such as Novak Djokovic, Andy Murray and Rafael Nadal are passed fit to play.