By Tripp Mateschitz, Lawn Tennis Correspondent, Posted: Thursday, October 16, 2008 11:20am PST USA

MADRID/ZURICH--(lawntennismag.com) US Open champion Serena Williams is the only American who has qualified for one of tennis' two year end championships, but even she is doubtful due to injury. After winning her ninth career grand slam in New York last month at the US Open, Serena Williams has played only one WTA Tour tennis match. Two weeks ago, Williams lost 0-6, 6-1, 6-4 to Na Li of China in the round of sixteen at the Porsche Tennis Grand Prix at Stuttgart, Germany then withdrew from the doubles tournament at Stuttgart with her sister Venus Williams. Americans Andy Roddick, Venus Williams and James Blake

Venus Williams has only played the WTA Tour's year end championships twice ever, finishing as a semifinalist both times in 1999 and 2002. Serena Williams also withdrew last week from the Kremlin Cup at Moscow, Russia with an ankle injury before the start of the tournament. Williams is not scheduled to compete again prior to the WTA Tour's year end tournament, the Sony Ericsson Championships which is to be contested the week of November 3rd at Doha, Qatar. Due to her injury, Williams' participation is questionable. Wimbledon champion Venus Williams stands at 8th place in the race of WTA Tour players to qualify for the 8 player tournament in Doha. But since her quarterfinal finish at the US Open, Williams has suffered two surprising losses which have prevented her from sealing her place at Doha. Williams lost at Stuttgart in the semifinals to world number one Jelena Jankovic of Serbia 6-7(8-10), 7-5, 6-2 after leading 7-6, 5-6. Last week at Moscow, Williams lost her opening round match to Flavia Pennetta of Italy 6-4, 2-6, 6-4. Williams won her opening round match this week at the Zurich Open at Zurich, Switzerland and could gain enough points with a title win this week to secure her Doha spot. Venus Williams has only played the WTA Tour's year end championships twice ever, finishing as a semifinalist both times in 1999 and 2002. In 2002, Williams left the court in tears after retiring down 0-5 due to injury. That Williams finished college earlier this year also should increase the likelihood of her participation in Doha. America's two ATP Tour year end championships hopes, James Blake and Andy Roddick both lost early this week at the Mutua Madrileņa Masters Madrid at Madrid, Spain. Currently they hold the last two positions in the eight man race to the Tennis Masters Cup Shanghai, which is to be played the week of November 10th. But both Roddick and Blake could be overtaken in the standings before November. Roddick finished as semifinalist at the Masters Cup in 2003, 2004 and last year. In his lone appearance at the Masters Cup in 2006, Blake lost in the final 6-0, 6-3, 6-4 to world number two Roger Federer of Switzerland. Share: Facebook Digg