Caroline Wozniacki's Australian Open preparations took a hit on Monday when she was forced to withdraw from her first-round match at the Sydney International with a wrist injury.

Wozniacki had dropped the first set to Barbora Zahlavova Styrcova of the Czech Republic 6-4 and was tied at 1-1 in the second set when she walked to the net and indicated she couldn't continue.

The fourth-seeded Dane called for the trainer several times during the first set for treatment on her left wrist.

Wozniacki beat Zahlavova Strycova in three sets in the semifinals of the ASB Classic in Auckland, New Zealand, last week, before falling to Venus Williams in the final.

Zahlavova Strycova will now play Australia's Samantha Stosur in the second round.