The American was due to headline the field at the WTA 500, but she has admitted that she is “not quite ready” to return to action following a hectic North American hard-court swing as she has played 19 matches in just over a month.
Pegula started her campaign with a runners-up finish at the Washington DC Open and followed it up with a run to the round of 16 at the Canadian Open.
The 32-year-old then returned to the United States and lost the Cincinnati Open final before losing in the semi-final of the US Open.
“I’m really disappointed to have to withdraw from Singapore,” she wrote on social media.
“After a long and physically demanding few weeks at the US Open, I’m just not quite ready to get back on court and compete at the level I expect from myself.
“I was really looking forward to playing in Singapore and hope I can come back in the future.”
Organisers are yet to confirm who will replace Pegula in the draw, but she is the third seeded player to pull out of the event with the total number of withdrawals now sitting at seven.
World No 13 Diana Shnaider was due to be seeded fourth, but she withdrew along with fifth seed Sorana Cirstea (No 15).
Other players who have pulled out are Ekaterina Alexandrova, Anastasia Potapova, Ann Li and Clara Tauson, but it would not be a shock if more players decide not to play after the North American swing.
Pegula’s replacement in the draw is still to be confirmed while the likes of Alycia Parks, Daria Kasatkina, Talia Gibson and Aliaksandra Sasnovich have already bumped up into the main draw following earlier withdrawals.
World No 5 Mirra Andreeva will replace Pegula as the top seed in the draw and Amanda Anisimova will now headline the bottom half.
World No 18 Alex Eala will now be seeded third with Elise Mertens, Maja Chwalinska, Sara Bejlek, Maria Sakkari and Barbora Krejcikova completing the seeding list.
Mertens is the defending champion after she defeated Li in the final of the inaugural edition in February 2025, but there have been changes as the tournament was upgraded from a WTA 250 to a WTA 500 event while it switched to September.
