The German football association announced that Michael Ballack will not be playing in the opening World Cup match against Costa Rica starting at 6 p.m. local time in Munich.

"The risk is too great," said one medical official. Germany's World Cup  preparations had been clouded by confusion over whether Ballack would play amid reports of a rift between him and coach Jürgen Klinsmann.

Germany's most important player, suffering from a strained calf muscle after taking a knock in a test match against Colombia last Friday, declared late on Thursday he was fit to play, hours after Klinsmann announced he would be on the bench.

Ballack's statement put Klinsmann in a difficult position. Refusing to put Ballack in the starting line-up means the team may end up disappointing the tens of millions of Germans yearning to see their boys impress the world. But if Klinsmann had let him play, he would have risked Ballack worsening his calf injury. It would also have effectively rewarded the midfielder for going behind his back.

There have been conflicting reports about Ballack's match fitness all week. The head of Germany's World Cup organizing committee, soccer legend Franz Beckenbauer, said Klinsmann was right not to let Ballack play. "Muscle injuries are dangerous. One has to be very careful. If something happens to him now, the World Cup will be over for him," Beckenbauer told ZDF television. 

Ballack has been stung by media criticism that he behaved unprofessionally by not getting the calf problem treated until after he had spent last weekend at home with his family.

"What's being said and reported about me is bordering on slander," Ballack told reporters after arriving in Munich, where the opening match will be played. He said he was doing all he could to get fit and that he hadn't felt any pain in his leg until Sunday night. "The World Cup is the greatest event in my career so far."

He told Germany's mass-circulation Bild newspaper late on Thursday: "I have undergone intensive treatment. I feel fit, don't feel any pain anymore. I want to play."

There have been reports of tension between Klinsmann and Ballack over match tactics.

At a news conference last week, Ballack criticized Klinsmann's strategy of mounting fast attacks, saying: "We go forward much too fast and with much too much risk. If we lose the ball we don't have the right order and have to run to catch up."

Even without Ballack, Germany is widely expected to beat Costa Rica. Klinsmann has named Werder Bremen's Tim Borowski, 26, who has played well in recent test matches, as Ballack's replacement.

Analysts expect the German team to get through the first round -- not a monumental task given that its opponents Costa Rica, Ecuador and Poland aren't top class teams -- but have serious doubts about whether it can get much further given its lack of experience and dearth of world class players.

"We won't get beyond the quarter finals! The team is too weak for that," former Germany and Bayern Munich player Mario Basler wrote in a column for Bild.