HOPEFUL Brisbane International organisers are playing a waiting game for world No.1 Simona Halep to decide if she will headline their women’s field this summer.

Halep and world No.5 Karolina Pliskova are the big female names yet to commit publicly to a tournament in the first week of 2019.

Brisbane already has three top-10 women, fourth-ranked Naomi Osaka, seventh-ranked Petra Kvitova and eighth-ranked Sloane Stephens.

Australian Open champion Caroline Wozniacki will start her season in Auckland, which, like Brisbane, starts on December 31. Wimbledon winners Serena Williams, Angelique Kerber and Garbine Muguruza all chose the more low-key Hopman Cup in Perth.

Halep would have to switch to the Brisbane International from the less lucrative Shenzhen, China tournament, which she won in the corresponding week in 2018, before she wound off a run to the Australian Open final.

The 27-year-old Romanian has played at the Queensland Tennis Centre once, 2012, and has twice won the Shenzhen

Halep been ranked No.1 for all but four weeks this year and clinched the year-end No.1 ranking despite losing in the first round of her past three tournaments with the points from her first major title, won in Paris, and her Australian Open runner-up finish.

“I’m not sure what Simona is doing in week one, or Karolina,’’ Brisbane tournament director Cameron Pearson said. “The entries don’t close until mid-November and we will know more later about who’s coming from the top 10, but I’m really excited about the field we have.

“I know a lot more have indicated they are keen to play in Brisbane. We pay $US1 million in prizemoney (to women players, $US250,000 more than Shenzhen), which is the most in the first week of the year, so it’s only natural we will see a lot more of the top players coming into Brisbane.’’

Halep withdrew from this week’s Kremlin Cup in Moscow with a back injury, joining US Open champion Osaka, also with a back complaint, on the sidelines.

Stephens, the 2017 US Open champion, and Osaka are among the younger players who will be looking to sustain a run next year at the top ranking, of which Halep has not been a dominating custodian.

“Anyone who can win a Grand Slam event has the qualities to become No.1,’’ Pearson said.

“The women’s game has seen quite a changing period in the No.1 ranking in recent times, although Simona has been there quite consistently this year.

“I think we will see a number of players win more Grand Slam titles on the women’s side and Sloane will be one of those and can be No.1 at some point.’’

The Brisbane International will be a seven-day tournament, one day fewer than recent years, as there will be no matches on Sunday, December 30, which will be devoted now to a Kids’ Day and public practice sessions.

“We felt showcasing the finals together was a good initiative,’’ Pearson said.

“We wanted to make sure the quality of the matches was maximised early in the week and we could have all eight singles quarter-finals on Pat Rafter Arena.’’

World No.1 Rafael Nadal, dual Wimbledon champion Andy Murray, defending Brisbane champion Nick Kyrgios, Japan’s 2014 US Open runner-up Kei Nishikori and Australian No.2 John Millman are the men’s entrants so far disclosed.