Top seed Simona Halep has withdrawn from the Sydney International with gastroenteritis.

The world No.3 had been scheduled to open her campaign on Tuesday against Czech Karolina Pliskova, but said she was in no condition to play.

Halep said she hoped to be fully recovered for the Australian Open starting on Monday in Melbourne.

The Romanian opened the 2015 season in style by collecting her ninth career title in Shenzhen, but admitted it was in China where she first fell ill.