World No.6 Karolina Pliskova has withdrawn from the Sydney International on day one of the tournament due to a thigh injury.
The US Open finalist was seeded fourth in Sydney but her withdrawal means Italian Roberta Vinci will move up in the seedings.
“Karolina is a fantastic player and someone we have loved watching on court in Sydney the past few years, said tournament director Alistair Macdonald.
“I wish her all the best with her recovery and look forward to welcoming her back to the tournament in 2018.
Play in Sydney begins on Sunday featuring world No.9 Svetlana Kuznetsova and 2016 finalist Monia Puig.