Germany coach Joachim Loew admitted heat and tiredness prevented his side from playing to their usual standard during Friday's 1-1 draw with China in Shanghai.
The Euro 2008 runners-up came from behind thanks to a goal from Lukas Podolski to clinch a draw but gave the impression that they were struggling for energy throughout.
Nevertheless, Loew defended the decision to stage a post-season tour of Asia, claiming it is a vital experience, particularly for the newcomers to the squad.
"We could all see that not everything went as we wanted it," he said. "We were not able to maintain a high tempo for 90 minutes. The players wanted to, but they simply couldn't do it.
"Despite everything, I think that some players who were with us for the first time have gained some good experience. They could feel the atmosphere of being with the national team and that alone is valuable. I think we have made a good impression overall here in China."
Germany now travel to Dubai where they face the United Arab Emirates in another friendly on Tuesday, and Loew intends to use that game for yet more experimentation.
On Friday, he left Mario Gomez alone in attack, playing with five midfielders before reverting to a standard 4-4-2 formation when Gomez was replaced by Cacau.
Loew defended his decision not to play the two Stuttgart strikers together.
"I know how they can play together so maybe it was better trying Cacau with Podolski or Cacau with (Miroslav) Klose to see how they get on together," he explained. "I am a coach who rather likes to experiment and in a phase like this, I would really like to try out a few things.
"That is why I am delighted to have the chance to see individual players. Games like these are ideal for me to gain important indications for those games when it really matters."
Germany's next important game is in August when they travel to Azerbaijan for a World Cup qualifier before heading to Russia in October for a game which could be decisive in their qualifying group.
Germany lead Group Four by four points from Russia, who have a game in hand.