Serena Williams seeded 28th at U.S. Open

Serena Williams will return to the U.S. Open for the first time in two years as a low No. 28 seed but with widespread expectations she could win a 14th major tournament championship.

Caroline Wozniacki, the 21-year-old Dane who was the Open runner-up in 2009 and a semifinalist last year, is the top seed, followed by Russians Vera Zvonareva, last year's runner-up, and Maria Sharapova, the 2006 Open champion.

The 32 seeds, announced Tuesday, are in the exact order of the world rankings, except for two absent players: Third-ranked Kim Clijsters, winner of the last two Opens, withdrew last week with an abdominal injury, and 22-year-old Russian Alisa Kleybanova, ranked 30th, has been undergoing treatment since being diagnosed with Hodgkin's lymphoma in July.

Williams, 30, had fallen to 172nd in the rankings during a year away from competition because of a foot injury and blood clots on her lungs. But back-to-back tournament victories in Open tuneups this summer boosted her ranking just high enough to assure she would be seeded -- and therefore guaranteed of not playing another seeded player for at least two rounds -- in the year's final Grand Slam event, which runs from Monday through Sept. 11.

Williams' older sister Venus, the Open champ in 2000 and 2001 and recently dealing with a virus, currently is ranked 36th and therefore not seeded. Besides the Williamses, other former Open champions in the field are Sharapova and No. 15 seed Svetlana Kuznetsova.

Victoria Azarenka of Belarus is seeded fourth, reigning Wimbledon champion Petra Kvitova is seeded fifth and the two most recent French Open champions, Li Na and Francesca Schiavone, are seeded sixth and seventh, respectively. Ana Ivanovic, the 2008 French champ, is No. 16.