NEW YORK, NY - AUGUST 31:  Maria Sharapova of Russia returns a shot against Caroline Wozniacki of Denmark during their women's singles fourth round match on Day Seven of the 2014 US Open at the USTA Billie Jean King National Tennis Center on August 31, 2014 in the Flushing neighborhood of the Queens borough of New York City.  (Photo by Matthew Stockman/Getty Images)