I no longer want to wear the German national team shirt. I think what I have achieved since my international debut in 2009 has been forgotten.

With these words, Germany's World Cup winning midfielder Mesut Ozil quit international football last night. 

Source: Talk Sport

He made the announcement with this tweet. 

It was coming, we knew it, but no one expected that it would happen solely because Ozil, who also has a Turkish descent, was constantly made to feel like an outsider in his country.

Source: Sky Sports

Germany did not perform well in the World Cup and there is no way to put it subtly. 

And immediately after their group stage ouster, the blame game began, at the centre of which was Ozil. 

Source: Metro.Co.UK

He faced criticism for not playing well but more than that, for meeting the Turkish president, Recep Tayyip Erdogan in May. 

Source: ITV

This is what broke him. 

If a newspaper or a pundit finds faults in a game I play in, then I can accept this. I am not a perfect footballer but what can't accept is German media outlets repeatedly questioning my dual heritage.
Source: Fox Sports
For me, having a picture with President Erdoğan wasn’t about politics or elections, it was about me respecting the highest office of my family’s country.
Source: Joe

Expressing his anger towards the president of the DFB, Reinhard Grindel, Ozil added:

People with racially discriminative backgrounds should not be allowed to work in the largest football federation in the world that has players from dual‑heritage families. In the eyes of Grindel and his supporters, I am German when we win but I am an immigrant when we lose.
Source: Eurosport

He ended his note with these heartbreaking lines:

It is with a heavy heart and after much consideration that because of recent events I will no longer be playing for Germany at international level whilst I have this feeling of racism and disrespect. This is not why I play football I will not sit back and do nothing about it. Racism should never, ever be accepted. 
Source: Four Four Two

Ozil, arguably the most gifted German footballer of his generation, the guy who held the World Cup trophy for Germany after their victory in 2014, is bowing out of the international football because he doesn't feel accepted in his country and there couldn't be anything more unfortunate than that.