Dietmar Hamann has accused the German football association of "weak leadership" for allowing criticism of Mesut Ozil to grow.
The 29-year-old shocked the football world on Sunday by stating that he no longer wants to play for Germany, citing "racism and disrespect" within German football.
Ozil, who has Turkish ancestry, has been heavily criticised in Germany for appearing in a picture with controversial Turkish president Recep Tayyip Erdogan, who has been accused of abusing human rights laws and restricting the freedom of the press, before the World Cup.
Announcing his international retirement via an open letter on social media, the Arsenal man also stated that he was scapegoated for his country's poor displays at the 2018 World Cup, which culminated in their worst showing at the tournament since 1938.
"What happened to this guy leaves a nasty taste in my mouth," Hamann, capped 59 times for Germany, told Sky Sports News.
"Of course, his behaviour was not clever by taking this picture just before the World Cup. But the DFB should have taken care of this. Now everybody is swinging at him. His qualities are questioned. We should stay strong. We shouldn't become populistic.
"It is a fact that the DFB should have behaved differently after the picture was taken. This problem should have been solved before the World Cup. Bad work from the DFB. And weak leadership. They just let the problem grow. That's why everybody started attacking Ozil."
Ozil has won 92 caps for Germany since his debut in 2009, scoring 23 goals in the process, and helped the nation claim their fourth World Cup title at Brazil 2014.
