While on the books at Chelsea, Marin spent most of his time out on loan. The German midfielder had loan spells at Sevilla, Fiorentina, Anderlecht and Trabzonspor.
Last season, Marin played in the Turkish Super Lig for Trabzonspor where he played 29 games and scored 2 goals in all competitions.
Marin also has 16 caps for Germany and has scored one international goal.