Wimbledon champion Roger Federer of Switzerland and Germany's Rainer Schuettler expressed their disappointment at the facility on the eve of the $3.7 million tournament that will also decide the year-end world number one ranking.
The biggest complaint being heard at the Westside Tennis Club is that the new $10 million stadium court, constructed specifically for the Masters Cup, slants noticeably at one end and has an undulating surface.
"All the players have complained about it," sixth seed Schuettler told reporters on Sunday. "For sure, this hardcourt is a very bad one."
Federer, who has an outside chance of claiming the top ranking ahead of current number one and U.S. Open champion Andy Roddick and second-seeded French Open winner Juan Carlos Ferrero of Spain, agreed with Schuettler.
Even with every session this week sold out, with only 7,500 seats this year's finale will not come close to matching the attendances the last two years in Shanghai and Sydney.
Last year's Masters Cup in Shanghai regularly attracted sellout audiences of 10,000.
The 2001 finale in Sydney also provided the largest crowd for a tennis match in Australia in 50 years with 16,800 fans watching Lleyton Hewitt defeat Pat Rafter.
This year's season-ending event is also the first to be staged outdoors since Australia in 1974 when Guillermo Vilas beat Ilie Nastase in the final.
"I would have liked it a bit bigger to fit more people," said Federer.
"Also, it is strange to be playing outdoors after the indoor season. We all have a feeling that the court is going downhill."
Fifth seed Andre Agassi, playing in his 13th year-end event, said the court had its peculiarities but the eight-times Grand Slam winner was also quick to defend the Westside facility.
"There's no question this court has its own personality," said Agassi, who has been training there for the last week.
"But at the end of the day two guys have to deal with it and that's what tennis is all about. Every court has it's own personality."