Women of the Australian Open

The reigning World No. 1, who withdrew from her Brisbane semi-final against Serena Williams after failing to recover from a toe infection, says she's not entering the competition with the mentality of defending the title she won 12 months ago. Still, she says, she's there "to win, to play tennis".

(Image: Chris Hyde/Getty Images)

World No. 1 Victoria Azarenka: Defending champion

Despite being plagued by injury and not winning a single match this year, the 2011 US Open winner and local favourite has not been ruled out as a strong challenger.

"She definitely has had some tough times here but I know on any given day she can bring her A-game. Everybody know how dangerous of an opponent she is" said fellow player Victoria Azarenka.

(Image: ALEXANDER NEMENOV/AFP/Getty Images)

Sam Stosur still a challenger to watch

World No. 4 Agnieszka Radwanska crushed her opponent Dominika Cibulkova in the final of the Apia International Sydney and has become a real threat to Victoria Azarenka, Maria Sharapova and Serena Williams.

Since 1968, the winner in Sydney has gone on to win the Australian Open 23 times.

"I think we can see this tournament is a critical lead-up to the Australian Open, certainly for the women, and the stats support that," Apia International tournament director Craig Watson said.

"We have seen it in the last couple of years with Azarenka winning in Sydney and then winning the Australian Open, and the year before Kim Clijsters and Li Na playing our final and then repeating in the Australian Open final."

(Image: Mark Nolan/Getty Images)

Agnieszka Radwanska on a roll after Sydney victory

Last year, she became only the sixth woman to complete a career slam.

Maria Sharapova, along with Victoria Azarenka, are seen as the biggest threats to Williams winning her 16th Grand Slam, although her early games have been hampered by a collarbone injury.

Pictured at the US Open in September 2012 (Image: Mike Stobe/Getty Images)

Maria Sharapova still a tough opponent

Asia's first grand slam singles champion Li Na is a crowd favorite after becoming runner-up to Kim Clijsters in 2011.

Asked whether she was happy not to have to challenge the retired Clijsters again, Li said: "Why should I be happy? I was really looking forward to playing her again.

"I played her last year in the fourth round. I never had a chance to come back, so I'm not happy."

(Image: PORNCHAI KITTIWONGSAKUL/AFP/Getty Images)

Li Na the crowd favourite

The former World No.1 has flown under the radar lately, having lost in the first and second rounds of tournaments in Brisbane and Sydney in the lead up to Melbourne.

A quality win in her first round match against Sabine Lisicki could finally set her up for the tournament.

Pictured playing a shot on a mirror court at the Adidas by Stella McCartney media launch on January 13, 2013 in Melbourne, Australia (Image: Scott Barbour/Getty Images)

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