Sydney: French Open champion Li Na will face a stern test of her early-season form when she defends her Sydney International title from a high-class field from Sunday, with the Australian Open just a week away.
China's Li shocked Kim Clijsters in last year's final and she returns as one of several leading contenders, including nine of the women's top 10 and three reigning major-winners, in the Australian Open's last build-up event.
Denmark's Caroline Wozniacki is battling to defend her top ranking from Wimbledon champion Petra Kvitova, the current number two, while world number four Maria Sharapova is the only top-10 absentee, due to an ankle injury.
Buoyed by her Sydney win, Li reached the final at last year's Australian Open only to lose to Clijsters, but she then went on to make history as China's first Grand Slam winner at the French Open.
Li's performances dropped markedly in the second half of the year but she has shown positive signs at the Hopman Cup in Perth, winning her opening matches of the year in convincing fashion.
"After the French Open, I didn't do well. I lost all my confidence. But now I am getting better," Li, 29, said this week.
"I want to keep healthy for the whole season. I am not young any more. I don't have time to waste, so I have to focus every second.
"Every year is different, so maybe 2012 will be even better."
Denmark's Wozniacki, who is clinging to the top ranking by 115 points, runs a constant battle to silence critics who say she cannot be considered the world's best player until she has won a Grand Slam title.
"I always think I am improving, but the first couple of matches of the season are always a bit tough and you need to find your feet out there," she said at the Hopman Cup.
"As I keep playing more matches I will improve and start playing better."
Second-ranked Kvitova is also firmly in the spotlight after her landmark 2011, when she upset favourite Sharapova to win her first Grand Slam title at Wimbledon in July.
The left-hander, who became the third Czech woman to win Wimbledon and confirmed her ascendancy by winning the year-end WTA Championships, was a big mover on the WTA rankings on the back of her six individual titles.
"Every season is different," she said. "One year ago I was (ranked) 34, now I am two at the start of the season and everyone is seeing me on the court for the first time, and it's not always easy to play on the court."
Australia's Sam Stosur will hope to resurrect her form of September, when she stunned Serena Williams to win the US Open title.
Stosur was knocked out in the second round of this week's Brisbane International and is looking for more court time as she bids to become the first Australian woman to win her national Open since Chris O'Neil in 1978.
The adjoining ATP men's tournament is headed by former US Open champion and world number 11 Juan Martin del Potro of Argentina.
Other top-20 men's entrants are American John Isner (18), Frenchman Richard Gasquet (19) and Spaniard Feliciano Lopez (20), along with four-time Sydney winner and former world number one Lleyton Hewitt, now ranked at 186.
Last year's winner, Gilles Simon of France, has not returned to defend his title.