Ana Ivanovic has announced her retirement and has withdrawn from the ASB Classic starting in Auckland next week.

The 29-year-old Serbian tennis star made the surprise announcement on her Facebook page at 7am this morning NZT.

The former world No. 1 and French Open champion confirmed her impending absence from the tennis circuit, including the upcoming ASB Classic and the Australian Open.

Tennis insiders had speculated that Ivanovic was set to announce her retirement.

But there were also rumours that she could be pregnant.

Ivanovic’s absence is the second major setback for the upcoming fortnight of major Auckland tennis after Juan Martin Del Potro’s injury-enforced withdrawal from the men’s tournament last Saturday.

Ivanovic has been a popular figure in Auckland, and though her ranking has slipped to world No 63, she would have been a major drawcard at the ASB Classic.

Ana Ivanovic has been plagued by injury in the past few year. Photo / AP 

She beat Venus Williams to take the title in 2015 – in one of the best women’s finals seen at Stanley Street – and charmed everyone associated with the tournament that year with her easy going demaonour and friendly attitude towards fans and volunteers.

Ivanovic also enjoyed a visit to the Coromandel after her win, but had a surprise first round exit this year at the hands of English journeywoman Naomi Broady.

Ivanovic has struggled with injuries over the last two seasons and the past year was her worst WTA campaign in more than a decade.

The three time grand slam finalist ended the year outside the top 50 for the first time since 2004, and had first round losses at Wimbledon and New York. Ivanovic was also stopped in the third round at the Australian and French Opens, and announced after the US Open that she was taking a break from the WTA tour to rest a wrist injury.

Ivanovic married German football star Bastian Schweinsteiger, who plays in Manchester United, in Venice last July in a glitzy ceremony, and had made no secret of her desire to start a family in the coming years.

ASB Classic tournament director Karl Budge didn’t have any insider knowledge as to what Ivanovic’s announcement was going to be.

“Like most tennis people, I’ll be watching her Facebook page on Thursday morning,” said Budge, who said he hadn’t had any contact with Ivanovic’s team since the Serbian posted her cryptic tweet on Wednesday.

That message, which was posted on her Twitter and Facebook page, asked her “dear friends and supporters to tune in on Thursday (NZT) for “something I want to share with you all”.

Ana Ivanovic stats

Age: 29

Turned professional: 2004

Grand Slams finals: 2007 French Open (L), 2008 Australian Open (L) 2008 French Open (W).

Career tournament victories: 15

Career prize money: US$15.5 million ($22.39 million)