Germany captain Philipp Lahm has criticised the person who leaked Joachim Low's lineup ahead of the Greece clash.
The Bayern Munich defender, who opened the scoring in his side's 4-2 win in Gdansk, has been left furious by the leaked information, which he believes threatens to derail Germany's Euro 2012 challenge.
Miroslav Klose, Andre Schurrle and Marco Reus were all given starts in the quarter-final showdown, with Greece given plenty of time to prepare for the changes.
Lahm has said that the squad will be vigilant to ensure such leaks do not happen again.
"I think it's a great pity that leaks occur," said Lahm. "It really is a disgrace for the lineup to be in the public domain so early.
"The one with the problem is the guy who did it. He could be damaging the hopes of a nation. He doesn't understand how sport works.
"We won't be hiring a detective or anything, but it's a big issue. It must not happen again for the semi-final. Everyone in the squad should be absolutely aware who he passes that lineup on to. We have to be extra careful now."
Germany play Italy in Warsaw on Thursday.
