NEW YORK, NY - SEPTEMBER 05:  Shuai Peng of China reacts after getting injured during her women's singles semifinal match against Caroline Wozniacki of Denmark on Day Twelve of the 2014 US Open at the USTA Billie Jean King National Tennis Center on September 5, 2014 in the Flushing neighborhood of the Queens borough of New York City.  (Photo by Chris Trotman/Getty Images for USTA)