The WTA announced Williams’ withdrawal from the tournament a week before play begins next Sunday in Singapore, releasing a video from the 22-time Grand Slam singles champion.
Williams says she is “really, really bummed” to skip the event, but adds that her doctor “insists that I stay home and heal” her shoulder.
Adds the 35-year-old American: “It’s been a really tough year for me.”
She hasn’t played since losing to Karolina Pliskova in the U.S. Open semifinals in early September, a defeat that resulted in Williams ceding the No. 1 ranking to Angelique Kerber after a 3½-year stay at the top.
Williams played in only eight tournaments in 2016, winning two of them, including Wimbledon in July.