MANUFACTURERS Adidas claim that altitude is the main factor affecting the World Cup ball -- not its design -- as criticism from players grows. An Adidas spokesman said those who have had the most problems are nations who have not practised enough with it. "What is strange is that people are saying the ball is lighter and that is just not true," said Thomas Schaikvan, head of global public relations at Adidas. "Playing at altitude is not the same as playing at sea level. That is just plain science. "There are players who play in leagues with other balls, there are players who did not play in the Africa Cup of Nations, and players with other federations who have not practised with this ball. "Those are the players who take the most amount of time to get used to it." Algeria's Madjid Bougherra called the Jabulani "horrible" after the glaring mistake made by their goalkeeper Faouzi Chaouchi when he allowed the Slovenian's Robert Koren's shot to bounce past him in their 1-0 group C defeat. After Nigeria's 1-0 defeat by Argentina, Nigerian Etuhu said: "You can't head it [from goalkeeper's kicks]. You don't know where it's going to go. If you pass the ball into a player's feet, if it's off the ground, you don't know where its going to go. "It's the worst thing they could have done. It's so hard to play with." The Jabulani, from the Zulu word "to celebrate", came in for heavy criticism from goalkeepers prior to the start of the tournament. England's David James joined Australia's Mark Schwarzer, Italy's Gianluigi Buffon and Iker Casillas of Spain in castigating it. "The ball is dreadful. It's horrible, but it's horrible for everyone," said James. "There will undoubtedly be goals scored in this tournament which in previous tournaments with different balls wouldn't have been scored. It will allow extra goals, but leave some goalkeepers looking daft." Buffon added: "The trajectory is really unpredictable. Usually you get used to it, but in this case every touch comes with the unknown. "I noticed the first day that this Jabulani ball wasn't right. The World Cup brings together the best players in the world and to those players you must provide something decent. The new ball is not decent." Outfield players, too, have also raised concerns about the ball, including Brazil striker Luis Fabiano and Denmark's Daniel Agger, who had a Jabulani bounce off his back and into the wrong net after a header by teammate Simon Poulsen, gifting their Dutch rivals the first goal of their 2-0 victory. The Jabulani was supplied to all countries in February but the issue of practising with it over a concerted a period of time, either within competitive games in domestic leagues or when training with club or national sides, appears to be tied up with sponsorship. The new Jabulani ball has been extensively used in Germany's Bundesliga as well as France and Argentina -- all national sides sponsored by Adidas -- and a number of other national leagues. The Jabulani has also been used in Major League Soccer in the United States, who held England to a 1-1 draw on Saturday with goalkeeper Robert Green believing his error in allowing American forward Clint Dempsey's shot to squirm from his grasp was partly because of the movement of the ball. FIFA has not made a comment on criticism of the Jabulani ball. Gripes about the Jabulani ball are not new but none of the 32 teams at the World Cup has made an official complaint to FIFA. Of course, soccer players have a habit of complaining about every new development when it comes to tournament balls. The Teimgeist ball used at the 2006 World Cup in Germany was called the "flying ball" and the "helium ball" because of its perceived extended flight time, while the Fevernova ball from the 2002 World Cup co-hosted by Japan and South Korea was deemed too light and too bouncy. Adidas has been manufacturing the official World Cup balls since 1970 -- first from leather and later from synthetic materials -- and the current tournament is its 11th world championship in a row. As expected, the German firm has defended the Jabulani, with Schaikvan saying last month that "all the response we have had has been positive" and that the World Cup teams had been given the ball ahead of time so they could get used to it News agencies