2011 champion Samantha Stosur has withdrawn from this year’s US Open, citing a continuing wrist injury.

The Australian won her lone Grand Slam singles title in Flushing six years ago, stunning six-time US Open champion Serena Williams, 6-2, 6-3, in the final. She is the third former champion forced to withdraw from this year’s event due to injury, joining men’s winners Novak Djokovic and Stan Wawrinka.

Stosur, currently ranked No. 43 in the world, hasn’t played since the French Open, where she reached the fourth round before losing in three sets to eventual champion Jelena Ostapenko. Previously, she had won the Roland Garros tune-up in Strasbourg.

In addition to her run at the 2011 US open, Stosur reached the final at the 2010 French Open, where she fell to Italian Francesca Schiavone in a 98-minute battle. The 33-year-old has amassed a number of doubles titles, including the women’s doubles crown at Roland Garros in 2006 with American Lisa Raymond. Stosur also secured titles in mixed doubles at the at the 2005 Australian Open and at Wimbledon in both 2008 and 2014.

Stosur’s withdrawal moves German Annika Beck into the main draw.

The US Open takes place from Aug. 28 - Sept. 10.