Wimbledon champion Roger Federer has led the complaints about the court which will be used for the season-ending Masters Cup in Houston.
Ferrero v Nalbandian
Agassi v Federer
The elite eight-player tournament begins on Monday, with Federer, Andy Roddick and Juan Carlos Ferrero all vying for the world number one spot.
"We all have the feeling the court is going downhill," said Federer, the third seed for the tournament.
"It's leaning and it has waves in it. Sometimes the bounce is a bit off."
Australian Open champion Andre Agassi admitted he had also noticed problems with the surface but defended the $10m stadium court.
"I haven't experienced it too clearly," Agassi said.
"Every court has its personality. It slants a certain way, leans one way or another. I have been able to figure that out.
"I don't think it's anything that needs to be focused on in this tournament."
The main focus of the tournament is expected to be the battle between Ferrero and Roddick to end the year at the top of the world rankings, with Federer a long shot.
For the Swiss player to come out on top he would have to win the tournament, with Roddick losing every match and Ferrero winning only once.
Roddick, the US Open champion and current number one, only arrived in Houston on Sunday, having hosted a television show on Saturday night.
"I definitely enjoyed myself. It kept me away from the worries and all this stuff," he said.
"Now I come here fresh and ready to go.
"I have something big to play for which should make it very interesting. I'm excited to be here. It was one of my goals. I feel I have gone above and beyond that this year."
Ferrero is focused on his first match, a Monday meeting with eighth-ranked David Nalbandian of Argentina, after losing his Cup openers the past two years.
Juan Carlos Ferrero
"This year I hope to win my first match and not have the same troubles," said Ferrero, who lost his only prior meeting with Nalbandian on clay in Portugal last year.
French Open champion Ferrero has nonetheless always progressed beyond the round-robin stages, reaching the 2001 semi-finals and 2002 final.
"I gained a lot of experience from reaching the final last year," Ferrero said. "I knew I could play in a big final. That final helped give me a lot of confidence in myself."
Ferrero, Agassi, Nalbandian and Wimbledon winner Federer were drawn into the Red Group, which will see at least one Grand Slam champion ousted before Saturday's semi-finals.
Agassi meets Federer on Monday in his first match since losing to Ferrero in the US Open semi-finals after taking a break following the birth of his second child.
"I'm ready to go," Agassi said. "My mind and body are fresh. I haven't won a match in two years at this event. I can only improve on that."