Simona Halep returns a shot during her match with America's Madison Keys during the WTA Wuhan Open 2016 tennis tournament in Wuhan, Hubei province, Sept 29, 2016. [Photo/Xinhua]

Halep is one of four players to win three WTA singles titles in 2016 (also Azarenka, Kerber and Stephens), clinching her second Premier Mandatory trophy at the Madrid Open and back-to-back titles at the Bucharest Open and Rogers Cup in Montreal.

She has brought her win-loss record to 43-14 after reaching the Wuhan Open semifinals. In addition, Halep reached two semifinals at the International Sydney and Western & Southern Open in Cincinnati and four quarterfinals at the BNP Paribas Open in Indian Wells, Miami Open, Wimbledon and the US Open.

"It means a lot to qualify for the WTA Finals Singapore - it was one of my goals this year," said Halep. "It will be my third time in a row competing at the WTA Finals and I hope I play great. I have great memories from 2014 and am confident I can do well. I will be very focused."