Top-ranked Serena Williams will team with John Isner to represent the United States in a star-studded field at the Hopman Cup international tournament in January. Williams and Isner will join the Serbian pair of Novak Djokovic and Ana Ivanovic, Belgium's Justine Henin, Australia's Lleyton Hewitt and France's Gael Monfils in the mixed teams tournament that runs Jan. 1 through 8. Djokovic won the Australian Open in 2008 after reaching the Hopman Cup final with Jelena Jankovic and says the tournament provides an ideal prelude to the season's first Grand Slam event. "I'm looking forward to going back to the Hopman Cup," Djokovic said. "For me it was a good preparation for the Australian Open." Read more: http://sports.espn.go.com/sports/tennis/news/story?id=5433139