MELBOURNE, Australia -- Defending champions Novak Djokovic and Victoria Azarenka will be the top-seeded players for the Australian Open.

Organizers stuck closely to the latest rankings to seed 32 players for each of the men's and women's draws. The year's first Grand Slam tournament starts next week.

Djokovic is followed by Roger Federer, U.S. Open champion Andy Murray and David Ferrer. Ferrer replaces fellow Spaniard Rafael Nadal, who has withdrawn because a stomach ailment delayed his comeback from a knee injury.

Milos Raonic of Thornhill, Ont., is the top seeded Canadian at No. 14. Raonic, who dropped his opening match to an unseeded player at the Brisbane International last week, fell two positions to No. 15 in the latest ATP world rankings.

On the women's side, French Open champion Maria Sharapova is seeded second. Serena Williams, the reigning Wimbledon, Olympic and U.S. Open champion, is third.

Agnieszka Radwanska is seeded fourth, followed by Angelique Kerber and Li Na. American teenager Sloane Stephens is seeded after advancing to a No. 29 ranking.