Australia's Kewell winning fitness race

Australia forward Harry Kewell is winning his race to be fit for the Socceroos' opening World Cup game on June 13, coach Pim Verbeek said on Monday.

The Galatasaray forward did not train with the squad in their morning session but looks set to be included in Verbeek's final squad of 23 which will be announced after a warm-up game against Denmark on Tuesday.

The tournament starts on June 11 in South Africa and Australia play their first Group D game against former champions Germany two days later.

"Harry's OK, he will go through another tough training session tomorrow ... the expectation is that he will start training on Thursday with us," Verbeek told reporters at their Johannesburg training camp.

"It is good that we have 10 days and he is perfectly on track, that is exactly what we had planned."

Kewell, one of the 20th ranked Socceroos most high profile players, could play in the final friendly against the United States on Saturday.

Australia, who made it though the group stages at the 2006 World Cup, also face Ghana and Serbia.

Captain Lucas Neill, meanwhile, joined the growing list of players criticising the official World Cup ball.

"On the ground, in the air it makes control difficult and it means you have to watch the ball right onto your foot," he said.

"Any slight pass that is 10, 20 centimetres off target usually stays 10 or 20 centimetres off target and it's hard to reach."

The Adidas ball, known as "Jabulani" which means to celebrate in Zulu, is particularly tricky for goalkeepers.

"I feel sorry for the keepers most of all because the ball is going to move a helluva lot in the air," Neill said.

Spain goalkeeper Iker Casillas on Sunday described it as a "beachball" due to its light weight and unpredictable movement. Italy's Gianluigi Buffon slammed the ball as "shameful."