NEW YORK -- U.S. Open seedings released Monday include 32 men and 32 women, double last year's total, with Gustavo Kuerten and Martina Hingis seeded No. 1.

As in the past, seedings were based on tour rankings for the year's final Grand Slam event, which begins next Monday.

Martina Hingis gets the top women's seed for the fourth consecutive year.(AP)

"At this time there's no definitive system that makes sense for all four Grand Slams," Favorito said.

Anna Kournikova, seeded 19th, withdrew Monday because of a foot injury that has sidelined her most of the year. Unseeded Mary Pierce, a two-time quarterfinalist, pulled out because of a lower back injury.

The expansion to 32 seeded players in each draw for all major events was announced in June. It makes early-round upsets less likely and gives top players a better chance to advance, which pleases sponsors and TV networks.

Kuerten is seeded No. 1 at the U.S. Open for the first time. The Brazilian, bothered by soreness in his right side, quit seven games into Sunday's final against Patrick Rafter at a tournament in Indianapolis but said he expects to ready for the Open.

Two-time champion Andre Agassi is seeded second, followed by 2000 champion Marat Safin. Pete Sampras is 10th, his lowest seeding since winning the first of his four U.S. Open titles in 1990.

Thanks to the expanded seeding system, young American Andy Roddick is seeded in a Grand Slam tournament for the first time. The 18-year-old American, who won his first hard-court title Sunday at Washington, is seeded 18th.

Hingis is seeded No. 1 for a fourth straight year even though she hasn't won a Grand Slam title since January 1999. She won her only U.S. Open title in 1997.

Jennifer Capriati, who won this year's Australian and French Open titles, is seeded a career-best second. Lindsay Davenport is third, while Wimbledon champion Venus Williams is fourth and sister Serena is 10th.

With all top players entered, seeded players can't face an opponent ranked higher than 33rd until at least the third round. Previously, the No. 1 player conceivably could draw No. 17 in the first round.

The U.S. Open had seeded 16 men every year since 1972 and 16 women every year since 1978.

"There are more than 16 great players in tennis on both sides," Favorito said. "And with 32 seeds, you can still have first-round upsets. It's a very workable number."

Seeded players now represent 25 percent of each 128-player draw.