Tennis can be cruel at times. Ask Kei Nishikori … who worked hard on court as his contemporaries took some time off to enjoy Christmas with their near and dear ones.

The Japanese star has a reason to practice and only practice, though. His Australian Open participation is in doubt as he continues to deal with a right wrist injury.

“Busy Christmas. Morning practice today at the @IMGAcademy! Happy holidays everyone,” he captioned a video of himself training to his legions of followers on Twitter.

Nishikori, who ended his season in August and also missed the US Open this year, recently announced his withdrawal from the season-opening Brisbane International.

“I’m so disappointed to miss Brisbane this year. For years it’s been my first tournament of the season and I always feel so at home there,” he said.

Whether he makes it to the Australian Open – scheduled to begin on January 15 – only time will tell.

Busy Christmas ???? morning practice today at the @IMGAcademy! Happy holidays everyone. https://t.co/uLBRtWCbow pic.twitter.com/IDK7F6xstu

— Kei Nishikori (@keinishikori) December 25, 2017