Martina Hingis criticised the scheduling of her matches after losing to Jelena Jankovic in the quarter-finals of the Dubai Open.
Hingis had been hoping to win her second title in Dubai
Fifth seed Jankovic won 7-6 (7-3) 6-2 to set up a last-eight clash with second seed Amelie Mauresmo, who beat Daniela Hantuchova 6-3 3-6 6-4.
Hingis had finished her previous match at 1.30am before returning to face Jankovic in the afternoon.
"I don't think it's very fair to the players," said Hingis.
I would have done anything to have played sooner
"Maybe there is a chance in the future they'll work on this. I love this tournament so I don't want to be negative, but you've got to deal with the situation."
She added: "I felt I could sleep on court last night and I should go home but I stay here and play over again.
"You could tell I was fatigued. Jelena is a young and up-and-coming player and against her you have to be at your best.
"They have to do something - they can't put five matches on centre court at 2pm thinking everyone will play one-hour matches. I would have done anything to have played sooner.
"Maybe they will learn from this."
Mauresmo played with heavy strapping on both thighs as she battled past Hantuchova in three sets.
"The strappings are only a precaution," she said. "I felt really okay most of the time.
"But she had a hard serve and it gave me a lot of trouble today and I thought I could have done a lot better in that area of the game."
In the remaining quarter-finals, Svetlana Kuznetsova beat Patty Schnyder 6-3 6-4 and will face top seed Justine Henin, who thrashed Elena Daniilidou 6-0 6-2.