There will be a mixture of youth and experience among the eight WTA Finals contenders eager to take advantage of Serena Williams' absence in Singapore.

World number one Williams has won the season-ending extravaganza in the Far East three years in a row, but there will be a new champion in the $7million event this time around.

The legendary American opted to take the rest of 2015 off to recover from injuries after the anguish of a sensational US Open semi-final defeat to Roberta Vinci, which shattered her hopes of winning a first calendar grand slam.

Simona Halep takes the mantle of top seed and the world number two will be determined to banish the memories of losing to Williams in the final 12 months ago.

Halep won the tournament back in 2011, while Maria Sharapova is the only other previous WTA Finals winner who will be competing in the 2015 edition and the pair will face each other in the Red Group.

Romanian Halep has not played since retiring from the China Open due to an Achilles injury, while 2004 champion Sharapova has also been hampered by injuries, but both players are fit and plotting to end the season on a high note.

Halep, a winner of three hard-court titles this year, believes it is too difficult to predict who will come out on top ahead of the start of the round-robin tournament on Sunday.

"Everyone has a chance to win," she said. "The tournament is open, in my opinion.

"I'm fresh to start the tournament, but I also need to be very focused for the first [match because] when you start, it's difficult to play.

"I don't feel pressure. I am the top-ranked player here, but it's not a big deal in this tournament because everyone is in the top 10. Everyone plays good tennis at the highest level."

Flavia Pennetta has also been draw in the Red Group in what will be the last event of her career and the Italian will be looking to sign off in style as she remains on a high after winning the US Open last month. 

Agnieszka Radwanska is the fourth and final player in the Red Group, while the White Group includes the dangerous Garbine Muguruza, who has experienced a rapid rise this year.

Muguruza has surged to number five in the world and was runner-up to Williams at Wimbledon in her first grand slam final.

Petra Kvitova, Angelique Kerber and Lucie Safarova will also be aiming to make their presence felt in the White Group and go on to secure a lucrative victory.