FILE - In this July 3, 2010, file photo, Serena Williams of the United States, hits a forehand return to Russia's Vera Zvonareva during their women's singles final at the All England Lawn Tennis Championships at Wimbledon. Williams grabbed her racket and got out on a tennis court on Tuesday, April 12, 2011, which she said was her "first day back" after a series of health problems, including blood clots in her lung. The 13-time Grand Slam singles champion and former No. 1-ranked player has not played an official match since she won the title at Wimbledon in July. (AP Photo/Alastair Grant, File)