Former world No 1 Maria Sharapova and US Open finalist Madison Keys have pulled out of next week's Dubai Duty Free Tennis Championships.
Five-time Grand Slam winner Sharapova, who had a accepted a wildcard to make her first appearance at the tournament since 2006, decided to withdraw with a forearm injury.
Sharapova lost her opening-round match at the Qatar Open on Monday to Romania's Monica Niculescu in three sets and is currently ranked 41 in the world.
The 30-year-old Russian has a 21-10 win-loss record since her return from a doping ban last April.
American world No 14 Keys, who was expected to make her Dubai debut, has withdrawn due to illness.
"Unfortunately both Maria Sharapova and Madison Keys have regretfully had to withdraw from the Dubai Duty Free Tennis Championships due to injury and illness," tournament director Salah Tahlak said in a statement.
"We are sorry that neither Maria nor Madison will be able to play in Dubai, but we still have one of the strongest fields ever assembled for the WTA event.
"Maria said that she is very sorry she cannot be here and hopes to come back next year. We wish her and Madison a speedy recovery."
The tournament begins on Monday with world No 2 Simona Halep set to lead the field alongside defending champion Elina Svitolina.
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