NEW YORK, NY - SEPTEMBER 05:  Andy Roddick of the United States waves to the crowd after losing to Juan Martin Del Potro of Argentina during their men's singles fourth round match on Day Ten of the 2012 U.S. Open at the 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 Mike Stobe/Getty Images for USTA)