Seles joined a growing list of ailing players - Pete Sampras, Thomas Muster, Boris Becker and Gabriela Sabatini - when she withdrew from the Spanish Open in Madrid yesterday.
It was the sixth tournament of her comeback after being stabbed in the back in April 1993, and her first since competing in Tokyo almost four months ago.
That is when the joint world No 1 began to be nagged by pain in the left shoulder, which she hurt towards the end of her triumph at the Australian Open in January. Doctors have diagnosed tendinitis and a tear in the lining of the socket.
"I knew coming into this tournament that my shoulder was not yet where I wanted it to be," Seles said yesterday. The pain returned during Wednesday's match against Austria's Barbara Schett, which Seles won after saving five match points.
"I can play, but there is pain when I hit backhands, and serving is still very difficult," she said.
Seles has drawn a French wild card, Caroline Dhenin, in the first round, and is seeded to play Arantxa Sanchez Vicario in the semi-finals and Steffi Graf in the final.
Sampras and Muster, who are seeded to meet in the men's final, intend to compete in spite of their injuries. Muster, the defending champion, sprained an ankle, and Sampras hurt his back.
The Wimbledon champion is projected to meet Andre Agassi in the semi- finals, but may face the unseeded Sergi Bruguera in the second round and Jim Courier in the quarter-finals.
Tim Henman returns to match action against Kris Goossens, a Belgian Davis Cup player, while Greg Rusedski faces a qualifier.
Paris Open draw, Sporting Digest, page 27