The German midfielder won 59 caps for his country and scored five goals, the most famous of which being the last ever goal at the old Wembley stadium against England.
"It's not really a big surprise to me I wasn't in the squad," he said. "That's it for me now at international level. I'm 32 now and this would have been my last tournament."
"I haven't spoken to the manager for the last three months so I didn't think there was much chance of me being included."