Australian Open contenders Maria Sharapova and Simona Halep withdrew from the Brisbane International on Tuesday after suffering injuries less than two weeks before the first grand slam of the year.
Romanian top seed Halep was felled by inflammation in her left Achilles, an injury that hampered her 2015 campaign, but was hopeful of being fit in time for next week's event in Sydney.
Russian Sharapova, the defending champion, was nursing an arm injury which meant a premature exit and no matches at her only tournament before the Melbourne slam which begins on Jan 18.
"I hurt my forearm in practice a couple days ago and need to precautionary withdraw with the #AusOpen starting," Sharapova was quoted as saying by Brisbane tournament organizers.
Sharapova has long been dogged by injuries and missed last year's U.S. Open with a leg muscle injury and then suffered an arm injury on her return in China in October.
The world number four had been due to face compatriot Ekaterina Makarova in first round action later on Tuesday but was replaced by another Russian, lucky loser Margarita Gasparyan.
That match, on Pat Rafter Arena, was one of several to be delayed on Tuesday by rain on the east coast of Australia, causing further headaches for tournament organizers shorn of two of their biggest draw cards.
The injuries to Halep and 28-year-old Sharapova, five-times a grand slam singles champion, follow fitness concerns over Australian Open defending champion Serena Williams, who pulled out of her first match of the year at the Hopman Cup in Perth on Monday because of a knee complaint.
Halep, the world number two, was scheduled to face twice Australian Open champion Victoria Azarenka of Belarus in second round action after receiving a bye and she downplayed concerns about the injury being anything serious.
"I did an MRI and it's nothing dangerous, but it's still an inflammation," said Halep who was replaced in the draw by lucky loser Ysaline Bonaventure of Belgium.
"I have just to take a few days' rest."
U.S. Open finalist Roberta Vinci escaped any drama and became the first woman through to the last eight on the Brisbane hard courts after the Italian demolished Dominika Cibulkova 6-1 6-1.
In the men's draw, seeds David Goffin and Domini Thiem won on Tuesday to make the second round, where 17-times grand slam champion Roger Federer will begin from against German Tobias Kamke on Wednesday.