Tennis player Li Na of China cries during a retirement ceremony at the China Open tennis tournament in Beijing September 30, 2014. Li, Asia's only grand slam singles champion, announced her retirement from tennis earlier this month, succumbing to the effect of long-term knee injuries. [Photo/Agencies]

Reigning Australian Open champion Li Na and husband Jiang Shan are expecting their first child.

The retired dual Grand Slam winner announced her pregnancy at Rod Laver Arena, where she claimed the title a year ago, during a ceremony ahead of the night session on Monday's opening day of the tournament.

"This summer, Jiang Shan and I expect our first child," Li said, joking that her husband had got her pregnant quickly, like serving an ace.

Rod Laver Arena is a lucky place for Li as she played three finals there against different opponents.

Speculation surrounding her pregnancy had been rife as media and fans noticed she was wearing a baggy dress and sneakers during ceremonies.

The Chinese sports idol shocked fans by hanging up her racket in September, on the eve of a tournament in Wuhan, her home city.