The second-biggest tennis tournament in the U.S. after the U.S. Open was expected to begin on Monday.
The 32-year-old Russian is one of only 10 female players to hold a career Grand Slam and has won 36 professional titles.
The teenager crashed out of the Citi Open in Washington, D.C., after losing in straight sets to Kazakhstan's Zarina Diyas.
U.S. tennis's teenage sensation takes on Kazakhstan's Zarina Diyas in the Round of 32 of the Citi Open.
Teenage sensation Coco Gauff is among the players in action in Washington, D.C. this week alongside with U.S. number one Sloane Stephens.
Williams accused umpire Carlos Ramos of sexism after she was given three code violations during the U.S. Open final in September.
The Canadian is a fierce critic of Sharapova, saying the Russian should not have been welcomed back to tennis after her doping ban.
Sharapova beat Roberta Vinci upon her return from her doping ban on Wednesday.
She will be 31 in two years—time enough for a comeback.
This is an unusual way to prepare for an important match.
Anti-doping bodies must become more accountable to the athletes they serve.
The company suspended its relationship in the wake of the news.
It is the latest in a series of organizations to back away from Grand Slam winner.
Key questions about the drug the tennis star tested positive for in January.
Allegations of match-fixing have provoked an independent review of anti-corruption practices in tennis.
The multiple Grand Slam winner failed to turn up to a press conference after the defeat.