He told the Suddeutschen Zeitung: "I've been sure about it for a few days: I won't be playing anymore."
According to Hitzlsperger, his body was giving the "appropriate signals" that it was time to stop.
"I think it's enough," he said.
Although he continued to receive offers to resume his playing career, the newspaper reported, Hitzlsperger said: "I've noticed: I need something else."
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