World number six Karolina Pliskova has pulled out of the Sydney International with a left thigh injury, tournament organisers confirmed on Sunday.
Pliskova, who had been fourth seeded for the Sydney event, clinched a straight 6-0, 6-3 win against France's Alize Cornet to win the Brisbane International on Saturday.
As the Czech's withdrawal came before the start of the first match of the Sydney International, Italian Roberta Vinci as the next eligible seed took Pliskova's open spot and a qualifier/lucky loser would come into the draw, the organisers of the event quoted.
The 24-year-old is all set to replace Dominika Cibulkova at the fifth spot in the new rankings going to be released on Monday.
The current World No. 6, who was runner-up to world number one Angelique Kerber at last year's US Open, is one of the favourites for the Australian Open, which begins in Melbourne next week.