NEW YORK, NY - SEPTEMBER 05:  Andy Roddick of the United States waves to the crowd after losing to Juan Martin Del Potro of Argentina after their men's singles fourth round match on Day Ten of the 2012 US Open at USTA Billie Jean King National Tennis Center on September 5, 2012 in the Flushing neighborhood of the Queens borough of New York City.  (Photo by Matthew Stockman/Getty Images)