Germany coach Joachim Loew said there was no need for panic or radical change despite his team again looking defensively vulnerable in their shock 1-0 defeat to Mexico in the opening game of their World Cup defence.
"In the first half we played very badly. We were not able to impose our usual way of playing," Loew told a news conference.
"But we will not just break apart now and become headless and do something completely different. There is no need to break out in panic just because we have lost a match."
It is true that few would bet against Germany turning things round in their remaining games against Sweden and South Korea, but all is clearly not right with the four-times winners.
"Our cover was often not good and we were left many times with just Jerome (Boateng) and myself in the back," said centre back Hummels, one of several Germans who will not want to watch a replay of Hirving Lozano's 35th-minute goal.
"We were warned (in the warm-up games). We played exactly like we did against Saudi Arabia (when Germany won 2-1) only against a better opponent. That's why the first half was like it was and Mexico obviously deserved to win it.
"If seven or eight players are attacking then it is clear that our attacking power is greater," said Hummels. "But that is something that I have often talked about internally. I does not always bear fruit."
Toni Kroos recognised that Germany, the ultimate tournament team, were now facing an unusual situation. "We are now under pressure, we have to get six points from the next games," he said.
"Overall we had our chances but did not score. We just lost the ball up front far too easily, and Mexico had always two or three people up front whom we failed to block efficiently."
Loew was at a loss to explain the problems. "We did not cover the spaces, we did not play our usual attacking game, we lost possession too often and so had to cover big distances, so the Mexicans had space to counter-attack," he said.
"When it came to passing, we were a bit negligent, which is quite unfamiliar when I look at this team.
"We simply have to concentrate on our strong points that we have not been able to bring to bear in the last two matches."