The 10th-seeded American suffered a stress fracture in her left foot almost a month ago while practicing at her home in Sarasota, Fla. The injury forced her to withdraw from the Pacific Life Open at Indian Wells before the start of the tournament.
Seles, ranked 12th in the world, was replaced by Evie Dominikovic from Australia, who lost to French qualifier Marion Bartoli of France, 4-6, 7-6 (7-1), 6-1.
"I tried my hardest but unfortunately my foot is not 100 percent and hopefully I will recover soon," Seles said. "I love to play at this tournament and I am sad to see that I had to pull out today, but it is the best I can do for my health."
Third seed Kim Clijsters, who received a first-round bye along with the other 31 seeds, posted a 6-2, 6-2 victory over South Korean Yoon Jeon Cho in the second round.
Clijsters, who is coming off her first Tier I triumph at Indian Wells on Sunday, needed only 55 minutes.
"I didn't want her to come into the match, didn't want her to have a lead in the second set, because then she can get on a roll and play even better," Clijsters said. "I really wanted to finish it off and stay focused. Especially when the weather is very hot it's hard to stay focused for a long time as well."
Fifth-seed Daniela Hantuchova of Slovakia was eliminated by Australian Alicia Molik, 2-6, 7-5, 6-0, and No. 7 Lindsay Davenport of the United States thrashed Spain's Cristina Torrens Valero, 6-2, 6-1.
On the men's side, sixth-seeded American Andy Roddick held off French qualifier Cyril Saulnier, 6-7 (1-7), 7-6 (7-2), 6-4.
Former world No. 4 Tim Henman, who is fighting to revive his career after a shoulder operation in November, endured a 6-3, 6-4 loss to Nicolas Escude of France. It was 18th-seeded Henman's fourth loss in five matches since his return to the ATP last month.
Escude's compatriot, No. 11 Sebastien Grosjean, was ousted by American Mardy Fish, 6-4, 7-6 (7-3).