London, England - Stars from England, Brazil and Italy have joined forces to criticise the controversial new ball to be used in the World Cup, but the developer insists there will be no cause for concern once the tournament gets underway in South Africa.
The Adidas "Jabulani" ball has caused concern at training camps around the globe as the world's best players try it out ahead of the start of the World Cup on June 11.
It is believed to have an unpredictable swerving movement which makes its hard for goalkeepers and strikers to anticipate its direction in flight.
England goalkeeper David James says the ball is "horrible", Brazil forward Luis Fabiano calls it "weird" and Italy goalkeeper Gianluigi Buffon fears its "unpredictability" could ruin the World Cup.
However, Dr Andy Harland, who developed the ball at Loughborough University's Sports Technology Institute in England, said much of the criticism was due to the unfamiliar effects arising from teams playing at altitude as part of their pre-World Cup training.
"I've seen nothing that's concerned me," he said. "This ball has been around since December and been used since then around the world with very few comments.
"Teams have gone to altitude and you've seen comments come out in those circumstances.
"We've said all along it would affect the ball, but it should be said whichever ball you play with at altitude is going to be affected."
The ball is billed as the roundest ever made, a quality which would make it less stable in the air if not for a series of grooves on the surface designed to reduce aerodynamic problems.
Harland said not one team had contacted him to discuss the ball and added he was not surprised by the criticism.
"It's not entirely unexpected," he said. "Before every tournament players come out and voice their opinions.
"There are no secrets about this ball. The ball is designed to allow the very best players in the world to exhibit their skills."