Defending champion Maria Sharapova and top seed Simona Halep pulled out of the Brisbane International on Tuesday citing injuries, depriving the contest of two of its main drawcards.
Sharapova withdrew from the season-opening event with a left forearm injury, saying it was a precautionary move ahead of the Australian Open later this month.
"I hurt my forearm in practice a couple of days ago," the world number four and third seed said in a statement. "This is such a special event for me, especially being the defending champion.
"I'm looking forward to seeing all my fans in Brisbane next year," she added.
The 28-year-old Russian had been due to play fellow countrywoman Ekaterina Makarova in the first round later Tuesday.
Makarova will now take on qualifying lucky loser Margarita Gasparyan, another Russian.
Sharapova's decision not to risk her Australian Open campaign comes after the latter half of her 2015 season was wrecked by injuries, first to her right leg which forced her to miss the US Open.
She retired from her comeback match at the Wuhan Open in China in September with a left forearm injury, only returning for the WTA Tour finals in Singapore at the end of October. Sharapova was joined on the sidelines at Brisbane by Romanian world number two Halep later Tuesday, who blamed a left leg injury for her decision to pull out.
Halep said she first injured her Achilles in August and had been experiencing some pain over the past two weeks. "I thought that I was ready to play -- I came here like I wanted to play, to start the year here, but I cannot have a full match, and I thought that it's more important to be ready and to take a break," she told reporters.
Halep said she expected to be fit for the Australian Open and said she also intended to play in Sydney next week. "It's nothing dangerous," she said of the injury. "I did an MRI and it's nothing dangerous, but it's still an inflammation. I have just to take a few days' rest."
Halep was due to play former world number one Victoria Azarenka, from Belarus, in the second round. Azarenka will now also play a lucky loser from qualifying, Belgian Ysaline Bonaventure.