SINGAPORE (Oct 18): The first tennis balls of the 2016 BNP Paribas WTA Finals Singapore presented by SC Global will be struck on Sunday, but the tournament will do without one of its major drawcards for the second year in a row.

Serena Williams, the former world number one and winner of the show-piece event in 2014, has withdrawn due to injury.

Williams announced that a persistent shoulder injury had put paid to her hopes of appearing in the season-finale, which will be played in the city-state for the third time this year.

"It's been a really tough year for me, dealing with these shoulder injuries. My doctor insists that I stay home and heal it. I only have wonderful memories of playing in Singapore and I will really miss my fans," the 35-year-old said in a video posted on the WTA website on Monday.

Tennis fans will certainly mourn the absence of the 22-time Grand Slam singles champion, who was toppled by Germany's Angelique Kerber after 186 weeks at the summit of women's tennis. Williams has played only eight tournaments this year, winning Wimbledon and a WTA event in Rome, where she tied Steffi Graf for the Open era record of Grand Slam titles.

On the other hand, seven players have qualified for the tournament, which starts on October 23. Angelique Kerber, Agnieszka Radwanska, Simona Halep, Karolina Pliskova, Garbiñe Muguruza, Madison Keys and Dominika Cibulkova will be in Singapore while the withdrawal of Williams opens up the final qualification spot.

(See also: Top women’s tennis players glam up Singapore in season finale)

Britain's Johanna Konta is in pole position to qualify by ranking points but either Spain's Carla Suárez Navarro or Russia's Svetlana Kuznetsova can upset the odds by winning the VTB Kremlin Cup in Moscow this week to clinch the final place.