Stosur pulls out of US Open with wrist injury

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Sam Stosur has withdrawn from the US Open due to an ongoing wrist injury.

The 2011 champion has not played since the French Open, where she was knocked out by eventual champion Jelena Ostapenko in round four.

Stosur upset Serena Williams to clinch her only grand slam title at Flushing Meadows in 2011 and she is the third former champion to have pulled out across the men and women's draws with Novak Djokovic and Stan Wawrinka also absent.

Annika Beck is the beneficiary of Stosur's misfortune, with the German taking her place in the main draw.