Serena Williams, the Billie Jean King Cup’s defending champion, has withdrawn from the upcoming BNP Paribas Showdown, scheduled for Monday, March 1, 2010 at Madison Square Garden. Williams, who qualified for the Showdown based on her 2009 victories at both the Australian Open and Wimbledon, has withdrawn due to a leg injury sustained during her recent run to the Australian Open Championships. This injury has also forced Williams out of WTA events in Paris and Dubai.