Williams pulls out of Cincinnati Masters
American Serena Williams has announced she has withdrawn from the Cincinnati Masters due to a recurring back injury.
Her announcement comes just days after pulling out of the Rogers Cup final, where she was due to face Canadian Bianca Andreescu.
The 37-year-old had been hoping to prove her fitness before Tuesday's match with Zarina Divas in Cincinnati but has decided to skip another event.
Williams has now been forced to withdraw or retire from all five of her non-Grand Slam events this season.
Confirming her decision, she told reporters: "I am so sad to withdraw as it is truly one of the tournaments I most love to play.
"I came to Mason [Ohio] 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."
Williams is now facing a race against time to play at the US Open in two weeks, where she is chasing a record-equalling 24th Grand Slam title.
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