- Victoria Azarenka battling to be fit for Australian Open after having minor surgery on toe
- World No. 1 pulls out of Friday's semifinal against Serena Williams at Brisbane warmup event
- U.S. Open champion Williams will play Russia's Anastasia Pavlyuchenkova in final
- Andy Murary into semis of men's event, while Novak Djokovic will play in final of Hopman Cup
World No. 1 Victoria Azarenka suffered a blow in the preparations to her Australian Open title defense on Friday, pulling out of a much-anticipated rematch with Serena Williams due to a toe problem.
The Belorussian was due to play her U.S. Open final conqueror in the semis of the Brisbane International, her first top-level warmup event for the season's opening grand slam -- which starts on January 14.
World No. 2 Maria Sharapova is also battling to be fit for Melbourne, having withdrawn before the beginning of the Brisbane tournament due to a collarbone problem.
"It's a right toe infection -- it's been there for about 10 days and it's been getting worse," Azarenka told reporters.
"I had to take action on it, which I did yesterday -- it was a minor surgery, I had to take something out of my toe. And unfortunately I didn't have enough time to recover to be able to play the semifinals today."
The 23-year-old won her first grand slam title in Melbourne last January before going on to top the rankings and become the WTA Tour's leading prize money winner for 2012.