Host nation Germany enjoyed the perfect start to the World Cup with a 4-2 win over Costa Rica in the opening match, but doubts still linger over their defensive shortcomings.
Costa Rica caused Germany several problems at the back and their two goals will be a concern for Germany coach Jurgen Klinsmann.
When in attack, Germany always looked dangerous and Polish-born striker Miroslav Klose, celebrating his 28th birthday, was the match hero scoring a brace, while Philipp Lahm and Torsten Frings were also on target.
But at the other end the three-time winners looked fragile and former Manchester City striker Paulo Wanchope struck twice (11 minutes, 73 seconds) to give Germany the jitters.
"We can be content with the game. Getting three points was the main thing, and it is job done," Klinsmann said.
"It was an attractive game -- just as we promised. There was a bit of nervousness there and tension and we saw that for two goals conceded. That is not unusual for a first game," he said.
But while Klinsmann tried to gloss over the defensive flaws, he did admit they were there.
"We made mistakes, but we are working on that," Klinsmann said. "We are trying to filter back quickly. We have some practising to do."
Under Klinsmann the German team have adopted the "attack is the best form of defense" strategy, but match hero Klose admits it means there is little room for error.
"We have decided to be an attacking team and get forward at every opportunity," Klose said.
"We lost the ball a few times when going forward and that was the problem. We are good at getting behind teams, but tracking back is not so easy. We need to tighten up at the back when we lose possession," he said.
Franz Beckenbauer, a World Cup winner with West Germany in 1974 and now head of the organizing committee, was also concerned.
"We have been trying to cut out the defensive mistakes and make the backline more solid, but it does not seem to be working," he said.
"But we are off to a flier and that is all that counts. We can now prepare for Poland," Beckenbauer added.
Left back Lahm, buoyant after scoring his second international goal, admitted a clean sheet would have been nicer.
"It's very important to start with a win. But we shouldn't concede so many goals!" Lahm declared.
"But we look good at the other end and the fans deserve a lot of credit. They played a major part in this win as they really got behind us. They were the 12th man," he said.
Germany's next test is against Poland in Dortmund on Wednesday, and once again the defense will be under scrutiny.
Captain Michael Ballack, who missed the game with a calf injury, should be back for that match although he is likely to offer more of an attacking threat than defensive stability.
"It is a shame because I wanted to play but Klinsmann had to put the brakes on me and I have to accept that," Ballack said. "I am looking forward to the Poland game now and am preparing for that."
Klinsmann confirmed Ballack had trained on Friday without any recurrence of his calf problem and is expected to be fit to face Poland.