It is the second consecutive WTA event in two consecutive seasons when the former champion has decided not to play due to an injury.
The 37-year-old superstar, now ranked number 10th in the world, appeared to be moving freely with a 6-3, 1-6, 6-1 victory against Sweden’s Rebecca Peterson, inside Hard Rock Stadium, in the second round of the Miami Open.
Williams fell in a three-set battle with Czech Karolina Pliskova in the quarter-finals of the Australian Open in January.
In her first tournament since then, at Indian Wells this month, she defeated former world number one Victoria Azarenka in her opening match but then retired while trailing against another former No. 1, Garbine Muguruza, with a viral illness.
Williams didn’t mention any health issues during a news conference after the match, and the WTA had no information regarding when she got hurt.
Williams was next scheduled to play 18-seeded Qiang Wang, who advanced to the fourth round.