Germany's Kerber - who also competed at London 2012 before being runner-up in Rio four years later - said on social media it was "disappointing" she couldn't compete at the Games.

However the three-time grand slam champion said her body "needs rest" after an intensive grass-court season.

The 33-year-old Kerber ended a three-year trophy drought in Bad Homburg in the build-up to Wimbledon, where she reached the semi-finals before losing to eventual winner Ash Barty of Australia.

Kerber had intended to compete in singles and mixed doubles at Tokyo alongside Alexander Zverev.

She was also considered a candidate to be Germany's flag bearer at the opening ceremony.

Several other tennis players have withdrawn from Tokyo for various reasons including top stars Serena Williams, Rafael Nadal and Roger Federer.

Men's world No.1 Novak Djokovic - who is vying for a calendar year "golden slam" of all four majors plus Olympic gold - is still considering his participation.

Australian Associated Press