The big story of the summer is Serena Williams is out following surgery. No defending champ.

Venus Williams is out thanks to an injured stomach muscle. No Williams at all.

It's the first time since 1994 that an American woman wasn't the top seed. It's a big void that can be filled if everyone stays healthy and plays well, but that's the big question.

	Pam's Picks
	Shriver Former WTA Tour pro Pam Shriver is providing ESPN.com with in-depth analysis throughout Wimbledon. Shriver, a tennis analyst for ESPN, was ranked as high as No. 3 in singles play. She won 21 singles and 112 doubles crowns, including 22 Grand Slam titles.

Lindsay Davenport, Amelie Mauresmo, Jennifer Capriati and Chanda Rubin have all been injured this summer. It opens it up the draw for players who are playing well but flying under the radar screen such as Ai Sugiyama, Maggie Maleeva or Patty Schnyder. It will depend on who gets their game in shape and gets on a roll heading into Labor Day weekend.

This is the first time that Kim Clijsters has ever been the No. 1 seed in a major. But the pressure of trying to win her first major is much bigger than the pressure of being the No. 1 seed.

Countrywoman Justine Henin-Hardenne is seeded second. If you had told me 10 to 15 years ago that two Belgians would be No. 1 and 2 at the U.S. Open, I would have said get out of here -- it's unheard of. I've probably only met four professional Belgian tennis players in my life.

You've got seven Russians who are seeded in the top 32: Anastasia Myskina, Elena Dementieva, Vera Zvonareva, Elena Bovina, Nadia Petrova, Lina Krasnoroutskaya, Svetlana Kuznetsova. That's impressive (it was the same amount as the United States before Venus pulled out leaving six Americans). So 13 of the 32 seeds are from the United States or Russia.

But really it's the questions about the players' health that takes the certainty out of having a blockbuster last major. If it stays hot and people aren't match tough, they'll struggle even more.

Davenport's toe problems crop up unexpectedly. With Venus' withdrawal, Davenport is the only one who has won here before. If her toe withstands the pressure of seven matches in 14 days, she's got a good chance to take this thing.

Even Capriati has a shot. It would be just like Capriati to do the unexpected again. She is the Sampras going into the U.S. Open this year. It's been 19 months since she has won a championship.

Otherwise, either one of the Belgians could win it. Clijsters has not had outstanding success at the U.S. Open. It's the only major where she hasn't been to at least the semifinals. She's got a pretty good draw, although American Laura Granville could cause some problems. But it's Kuznetsova in the third round who will be her first test and let us see how she's handling the pressure.

Without Serena and Venus, Davenport, Capriati, Henin-Hardenne, Clijsters or Mauresmo all have a chance to win. All of them have their issues they've been dealing with psychologically. Henin-Hardenne has perhaps the most confidence to win.

But really it's going to come down to survival of the fittest.