Defending champion Caroline Wozniacki begins her WTA Finals campaign against Czech Karolina Pliskova in the opening night session on Sunday.

The Danish second seed has also been drawn in the same group as Petra Kvitova and Elina Svitolina.

Wimbledon champion Angelique Kerber, top seed in Simona Halep’s absence, plays Kiki Bertens on Monday.

US Open champion Naomi Osaka and Sloane Stephens – both debutants at the season finale – complete their group.

The tournament, which also includes a doubles event, has a total prize fund of £5.36m.

Singapore is hosting the season-ending WTA Finals for the last time before the event moves to Chinese city Shenzhen next year.

No Halep or Williams – who has qualified?

World number one Halep finished top of the Race to Singapore rankings after a stellar season that saw her win a maiden Grand Slam at the French Open in June.

However, the Romanian – a beaten finalist in 2014 – withdrew from the event on Thursday because of a lower-back injury.

That means Germany’s Kerber is the top seed, ahead of Australian Open winner Wozniacki, with the pair separated in the group stage draw and unable to meet before the semi-finals.

Three other Grand Slam winners – Osaka, Kvitova and Stephens – are also among the eight contenders.

Ukraine’s Svitolina and former world number one Pliskova qualified on Wednesday following Bertens’ defeat in the second round of the Kremlin Cup in Moscow.

But the Dutch player joined them in Singapore as the beneficiary of Halep’s withdrawal.

Another big name missing is 23-time Grand Slam champion Serena Williams, who only returned midway through the season after having her first child and has not qualified.

Wozniacki, who claimed her first Grand Slam at the Australian Open in January, comes into the finals having won the China Open this month.

“All the best players are here so there’s no easy matches,” Wozniacki said.

“I’m just excited to start the competition and do my best. As defending champion I want to defend my title and end the season on a high.”

Vote – who will be celebrating victory in Shanghai?

How does the tournament work?

The finals are the culmination of the WTA season and the singles title is contested by the eight players who have accumulated the most ranking points from 52 tournaments – including the four Grand Slams – over the year.

The eight singles players are seeded in terms of points accrued and split into two groups of four in a draw, which took place on Friday.

The groups are played in a round-robin format over the course of the week, with the top two players in each qualifying for the semi-finals on Saturday.

The winners meet in the final on Sunday at 12:30 BST (19:30 local time).

• Live scores, schedule and results
• Alerts: Get tennis news sent to your phone

British number one and top seed Kyle Edmund reached the European Open semi-finals after quarter-final opponent Ilya Ivashka withdrew through injury.

Ivashka, the 24-year-old world number 97 from Belarus, pulled out before the match with a thigh problem.

Edmund now plays fourth seed Richard Gasquet of France, who beat Jan-Lennard Struff 6-4 6-7 (4-7) 7-6 (11-9).

The other semi will be between another Frenchman, Gael Monfils, and Argentine second seed Diego Schwartzman.

Sixth seed Monfils saw off Canadian Vasek Pospisil 7-5 6-4, while Schwartzman, runner-up for the past two years at this tournament, knocked out Gilles Simon 6-4 6-3.

• Live scores, schedule and results
• Alerts: Get tennis news sent to your phone

British number one Johanna Konta’s season ended when she lost in the Kremlin Cup semi-finals to Russian sixth seed Daria Kasatkina in Moscow.

Konta was aiming to make her second WTA final of a difficult season but lost 6-4 6-3 in Friday’s semi-final.

After struggling for form and dropping out of the world’s top 40, the 27-year-old has been working with prospective new coach Dimitri Zavialoff in Russia.

She responded by reaching the last four and tested Kasatkina before fading.

Victories against Elise Mertens, Daria Gavrilova and Aliaksandra Sasnovich – all above 44th-ranked Konta in the world – look to have boosted the Briton’s confidence after a disappointing season which led to her splitting with coach Michael Joyce last week.

And there were further positive signs – particularly in a tight opening set – for Konta to take, despite defeat by 21-year-old Kasatkina, who is ranked 14th in the world and considered one of the brightest talents on the WTA Tour.

Konta saved four set points at 5-2 down in the opener and broke back in the next game for 5-4 – after Kasatkina had saved three break points – when the 21-year-old double faulted.

However, Konta could not build on that momentum. She lost her serve again in the next game as Kasatkina took the opener having won just one more point than her opponent.

The former Wimbledon semi-finalist made an encouraging start to the second set by breaking Kasatkina’s serve, only for the Russian to take control and move 4-1 ahead as Konta’s aggressive baseline game began to lose its effectiveness.

The Briton saved a match point at 5-2 but Kasatkina held serve in the next game to reach the Moscow final for the second successive year.

Kasatkina will face Tunisian qualifier Ons Jabeur in Saturday’s final.