The 15-year-old dropped out of the last round of qualifying in Austria.
The Czech will make her seventh career WTA Finals appearance.
Naomi Osaka has won back-to-back titles with her dad as coach.
Roger Federer talks his responsibility to fans and the sport.
The Austrian will make his fourth appearance at the ATP's season-ending championships.
US Open champion cites wrist injury in withdrawal.
Roger Federer received a hero's welcome in Shanghai.