Germany coach Joachim Low has voiced his dismay with his side's defending in their 3-3 international friendly draw against Paraguay on Wednesday.
Goals from Jose Ariel Nunez, Wilson Pittoni and Miguel Samudio helped the Paraguayans to a 3-2 half-time lead as Germany struggled at the back, before Lars Bender salvaged a draw after the interval with a well-taken volley.
"We made elementary mistakes, tactical mistakes, especially in the beginning. We lacked concentration," Low told reporters.
"Overall in the first half, the whole defence was very erratic. The opponent had too much space. But you could see some players were missing match practice. The freshness wasn't there.
"Of course the performances will improve once the players get into their seasons with their clubs. We will improve through September and October."
Skipper Philipp Lahm, meanwhile, was not too worried about his side's draw and is confident they will improve once the season gets going.
"I'm not worried. Next time we'll have time to work together, and we'll be better. It's normal when you have players coming together from different teams, all with different philosophies."
Germany are well placed to qualify for the 2014 World Cup, five points clear of second-placed Austria ahead of their meeting in September.