Marko Marin joined Chelsea from Werder Bremen for £7m three years ago in what now looks like a very poor move for both the player and the London club.
Since signing for the Blues, Marin has started just two Premier League matches.
The 26-year-old has been shipped out on loan four times, to Sevilla, Fiorentina, Anderlecht and Trabzonspor, where he is currently playing.
Trabzonspor have an option to sign Marin permanently for £2.8m and, according to Turkish paper AMK, he is “desperate” to leave Stamford Bridge for good.
Marin played 16 times for Germany’s senior team between 2008 and 2010.