American tennis star Serena Williams has withdrawn from the WTA Cincinnati Masters due to back injury.
Williams, a two-time Cincinnati champion, had retired during the Rogers Cup final Sunday in Toronto against Bianca Andreescu with the same injury.
The 23-time Grand Slam champion suffered the second blow just hours before her scheduled match began against qualifier Zarina Diyas.
“I am so sad to withdraw from the Western & Southern Open as it is truly one of the tournaments I most love to play,” the WTA website quoted Williams as saying in a statement.
“I came to Mason on Sunday and have tried everything to be ready to play tonight, and was still hopeful after my practice this morning. But unfortunately my back is still not right and I know I should not take to the court.”
The injury, however, has aroused concern over the 39-year-old player’s participation in the US Open scheduled from August 26.