The designer of the controversial Adidas Jabulani ball being used at the World Cup has said players are complaining "only because they are not used to it".
The ball was created at Loughborough University in England by Dr Andy Harland and colleagues, but it has not been well received.
Italy's Giampaolo Pazzini said it was "a catastrophe", Julio Cesar (Brazil) called it "terrible & like cheap ones you can buy in a supermarket", Spanish keeper Iker Casillas said it was "like a beachball & a rotten ball" while Germany's Marcus Hahnemann called it "a horse & the worst ball I've ever played with".
"The ball's terrible," USA 'keeper Tim Howard moaned. "You're going to hear that now, you're going to hear that next week and next month."
And referring to Robert Green's blunder on Saturday which cost England victory over USA, Steven Gerrard said: "We can't criticise the 'keeper &. The ball is tricky."
Speaking to ESPN, Dutch defender Johnny Heitinga said: "The ball played strange tricks every now and then," while winger Eljerio Elia said: "The ball bothered me. When it's played to you it goes in every direction."
Goalkeeper Maarten Stekelenburg said: "It was more to do with the altitude at which you're playing. I'm not the only one who's bothered by it." However, Harland has hit back. "I can categorically state there is nothing wrong with it," he told the Mirror. "We did years of research to get it right. It has fewer panels than any other football and therefore is true through the air. It's the most stable ever. I've heard the complaints but it's only because the players aren't used to the ball."
Harland added that he had offered to give England's players a talk about the ball before they left for South Africa but he had not been taken up on it.