Washington Kastles' Serena Williams makes a return during a singles pairing against the Boston Lobsters in a World Team Tennis match at Ferncroft Country Club in Middleton, Mass., Thursday, July 9, 2009.

Washington Kastles' Serena Williams pumps her fist after winning a point in her doubles match with Leander Paes against the Boston Lobsters during a World Team Tennis match at Ferncroft Country Club in Middleton, Mass., Thursday, July 9, 2009.

Washington Kastles' Serena Williams laughs on the bench during a World Team Tennis match against the Boston Lobsters at Ferncroft Country Club in Middleton, Mass., Thursday, July 9, 2009.

Washington Kastles' Serena Williams eyes a return during a game against the Boston Lobsters in a World Team Tennis match at Ferncroft Country Club in Middleton, Mass., Thursday, July 9, 2009.

Washington Kastles' Serena Williams is introduced along with teammates Olga Puchkova, right, and Scott Oudsema prior to matches against the Boston Lobsters in a World Team Tennis match in Middleton, Mass., Thursday, July 9, 2009.

Flavia Pennetta of Italy returns a ball to Alla Kudryatseva of Russia (unseen) during the quarter final Swedish Open Women's WTA tennis match in Bastad, on July 9, 2009. Pennetta won 6-4, 6-2. AFP PHOTO/ Bjorn Larsson Rosvall/Scanpix **SWEDEN OUT** (Photo credit should read BJORN LARSSON ROSVALL/AFP/Getty Images)

Flavia Pennetta of Italy returns a ball to Alla Kudryatseva of Russia during the quarter final Swedish Open Women's WTA tennis match in Bastad, on July 9, 2009. Pennetta won 6-4, 6-2. AFP PHOTO/ Bjorn Larsson Rosvall/Scanpix **SWEDEN OUT** (Photo credit should read BJORN LARSSON ROSVALL/AFP/Getty Images)

Alla Kudryatseva of Russia returns a ball to Flavia Pennetta of Italy during the quarter final Swedish Open Women's WTA tennis match in Bastad, on July 9, 2009. Pennetta won 6-4, 6-2. AFP PHOTO/ Bjorn Larsson Rosvall/Scanpix **SWEDEN OUT** (Photo credit should read BJORN LARSSON ROSVALL/AFP/Getty Images)

Alla Kudryatseva of Russia returns a ball to Flavia Pennetta of Italy during the quarter final Swedish Open Women's WTA tennis match in Bastad, on July 9, 2009. Pennetta won 6-4, 6-2. AFP PHOTO/ Bjorn Larsson Rosvall/Scanpix **SWEDEN OUT** (Photo credit should read BJORN LARSSON ROSVALL/AFP/Getty Images)

Maria Elena Camerin of Italy plays a return to Patty Schnyder of Switzerland during their Tennis Women Gaz de France Suez Grand Prix second round match in Budapest, Hungary, Thursday, July 9, 2009. Schnyder defeated Camerin.