Key Biscayne:Top-seeded Maria Sharapova might have to go through the Williams sisters just to reach the quarterfinals of the Sony Ericsson Open starting on Wednesday.
Sharapova, the runner-up for the last two years to Svetlana Kuznetsova in 2006 and Kim Clijsters in 2005, has a bye into the second round, where she'll face either Chan Yung-jan of Taiwan or Nuria Llagostera Vives of Spain.
In the third round the Russian could meet Venus Williams, the champion in 1998, 1999 and 2001 but unseeded this year.
Williams, who opens against Yuliana Fedak of Ukraine, has played only one tournament this year, winning last month in Memphis for her 34th career title.
Sharapova and Williams last met in the 2005 Wimbledon final, which Venus won for her fifth major title.
The winner of a possible Sharapova-Williams clash could meet 13th-seeded Serena Williams in the fourth round.
Sharapova lost to Serena in the Australian Open final, Serena's eighth Grand Slam crown and last appearance on the tour.
Serena leads Venus 8-7 in matchups. They haven't met since the 2005 US Open fourth round.
However, Venus leads Serena 2-1 at Key Biscayne, including the 1999 final. Serena, who won three straight finals here from 2002-2004, meets Elena Likhovtseva of Russia or a qualifier in her opener.
Eighteen of the top 20 women are entered, with only No 3 Amelie Mauresmo and No 10 Elena Dementieva missing.
"This year it is an extremely tough draw, especially with the Williams sisters here," Kuznetsova said.
Men gear up
The men's field includes 19 of the top 20, minus only No 13 Mario Ancic.
Two-time defending champion Roger Federer, his 41-match winning streak ended in his opening match at last week's Pacific Life Open, had a bye into the second round, where he awaits Igor Andreev of Russia or wild card Sam Querrey.
Federer was seeded to meet either Tommy Haas or Tommy Robredo in the quarterfinals, with a possible showdown against Ivan Ljubicic in the semifinals for a repeat of last year's final.
Ljubicic could have a third-round match against former No. 1 Carlos Moya, the 2003 runner-up.
Two other potential third-round clashes highlight the bottom half of the men's draw, lining up Marat Safin against James Blake, and 18th-seeded Lleyton Hewitt versus No 12 Andy Murray.
Safin and Blake are 2-2 against each other, and the winner might play Novak Djokovic, the 19-year-old Serb who cracked the top 10 for the first time by reaching the Pacific Life Open final on Sunday.
Hewitt will start against three-time French Open champ Gustavo Kuerten or a qualifier. Hewitt or Murray faces a possible last 16 berth with fifth-seeded Fernando Gonzalez, the Australian Open runner-up.
World No 3 Andy Roddick, the 2004 winner, starts against Martin Vassallo Arguello of Argentina or Lee Hung-taik of South Korea. Waiting in the fourth round might be No 13 David Ferrer, who beat Roddick in the quarterfinals last year.
Rafael Nadal, who won the Pacific Life Open and ended a nine-month title drought, will play Jan Hernych of Czech Republic or a qualifier in the second round, and possibly Marcos Baghdatis in the fourth.
Justine Henin, second-seeded but the new No 1, will open against Vania King of the United States or Sun Tiantian of China, and two rounds later could meet Daniela Hantuchova, the Pacific Life Open winner.
Defending champion Kuznetsova, who last to Hantuchova on Sunday, was seeded to meet former two-time champ Martina Hingis in the quarterfinals.
The retiring Clijsters will play either Akiko Morigami of Japan or Aleksandra Wozniak of Canada.