Roger Federer of Switzerland attends a training session ahead of 2019 Australian Open at Melbourne Park in Melbourne, Australia, on Jan. 8, 2019. (Photos: Xinhua)

Australian Open Tennis Tournament will take place from Jan. 14 to 27.

Roger Federer of Switzerland attends a training session ahead of 2019 Australian Open at Melbourne Park in Melbourne, Australia, on Jan. 8, 2019.

Australian Open Tennis Tournament will take place from Jan. 14 to 27.

Roger Federer of Switzerland attends a training session ahead of 2019 Australian Open at Melbourne Park in Melbourne, Australia, on Jan. 8, 2019.