American world number four Jessica Pegula said doing business with Saudi Arabia can help the WTA in its quest to ensure equal prize money but it will carefully evaluate following other sports to the Gulf state.
Defending champion Ons Jabeur said on Monday she had withdrawn from the Madrid Open with a calf injury after retiring from the Stuttgart Open at the weekend.
Top-ranked Daniil Medvedev committed 11 double-faults in falling to Stefanos Tsitsipas 7-6 (8/6), 3-6, 6-3 in Sunday's semi-finals of the ATP and WTA Cincinnati Masters.
Four-time Grand Slam champion Naomi Osaka made a triumphant return from a two-month layoff by defeating Chinese teen Zheng Qinwen on Tuesday at the WTA San Jose hardcourt tournament.
Reigning Wimbledon champion Elena Rybakina of Kazakhstan lost to seventh seed Daria Kasatkina on Monday in a first-round match at the WTA San Jose hardcourt tournament.
The head of women's tennis has condemned Madrid Open organisers for allowing controversial Romanian Fed Cup captain Ilie Nastase to take part in the trophy presentation ceremony following Saturday's final.