"I am totally optimistic," Voeller said after the triple world champions outplayed their modest hosts at the local stadium near Germany's training camp in this southern Japanese seaside resort.

"I am convinced we will have a good World Cup," added the former Germany striker, who had previously been cautious about his team's chances at the tournament in South Korea and Japan starting on Friday.

After losing a number of important players through injury, notably defensive marshal Jens Nowotny and creative midfielder Sebastian Deisler, Voeller said reaching the knock-out stages was his minimum aim.

But positive impressions from the team's first training sessions in Japan and Sunday's convincing display have left him wondering whether he can afford to be more ambitious.

"We may cause a surprise," he said after Germany's final match before they play Saudi Arabia in their opening group E game on Saturday in Sapporo.

Voeller, whose side also face Cameroon and Ireland in the group stages, was perfectly aware that the demolition of brave but limited under-18 Japanese players had little significance but he was still pleased.

"I have always said that those warm-up matches are not that relevant," he said. "This was little more than a training session but it was an enjoyable one."

REHMER COMEBACK

Voeller tried out all the outfield players in his squad except inspirational midfielder Michael Ballack, who has been nursing a bruised foot and trained on Saturday for the first time since the team arrived in Japan.

"Michael trained again today (Sunday) and I have no doubt he will be able to play our first match," Voeller said.

The Germany coach, who lifted the World Cup as a player in 1990, changed his side totally at halftime with the exception of Marko Rehmer.

Only the Hertha Berlin player, who has been hit by a series of injuries and had not played a competitive match since last March, played the full 90 minutes.

"I still have some work to do in training but I felt fine," said Rehmer, who sprained his shoulder a few days before the trip to Asia.

Cheered on by 15,000 spectators waving flags and having a great time on a pleasant afternoon, Germany made a tentative start and the floodgates did not open until defender Thomas Linke headed home in the 17th minute.

"The only thing I can regret is that we wasted too many chances in the opening stages," Voeller said. "Apart from that is was all fine. We combined well at times, we scored plenty of goals and nobody got hurt."

Three goals followed Linke's effort before the break, then six more after the interval, including two each from strikers Oliver Bierhoff and Oliver Neuville.

One of the day's main winners was Kaiserslautern forward Miroslav Klose, who scored one goal and set up two, prompting Voeller to say he would be in the starting line-up against Saudi Arabia.

"Miro (Miroslav) is in great shape and he will play on Saturday," said Voeller, who refused to drop any other hints, apart from the fact that Germany captain Oliver Kahn will be in goal.