Former No. 1 Caroline Wozniacki stopped playing her second-round match at the Citi Open against Sam Stosur because of an injured left arm.
The right-handed Wozniacki said that she felt pain while hitting a two-handed backhand at 5-all in the first set. She was treated by a trainer and wound up winning that set 7-5, but retired after getting broken to trail 4-3 in the second.
It’s the latest in a series of setbacks this season for Wozniacki, the U.S. Open runner-up in 2009 and 2014. She hasn’t won a Grand Slam match this year, losing in the first round at the Australian Open and Wimbledon and missing the French Open because of an injured ankle.
Wozniacki is supposed to represent Denmark at the Rio de Janiero Olympics next month and carry her country’s flag in the opening ceremony.