Mark Philippoussis withdrew from the Sydney International tennis tournament as expected on Sunday after suffering a groin injury during the Hopman Cup.
His participation in the Australian Open, which begins on 17 January in Melbourne, also remains in doubt.
Defending women's champion Justine Henin-Hardenne is also out of the Sydney event because of a knee injury.
In the only main draw men's or women's singles match on Sunday, Nathalie Dechy beat American Lisa Raymond 7-5 6-3.
Number one men's seed Lleyton Hewitt begins his quest for a fourth Sydney title on Tuesday when he plays Karol Beck.
Lindsay Davenport, top seed in the women's draw, has been handed a first-round bye and plays France's Dechy in the second round on Tuesday.