He featured just 15 times in all competitions, as poor form and injury problems cost him a place in the first-team.
This summer, with plenty of competition in the attacking midfield position, his time at Chelsea looked to be over.
However he is still young so Chelsea decided not give up on him just yet - so instead they sent him out on loan to Spanish outfit Sevilla.
He impressed in Spain at the start of the season but unfortunately, once again, fitness issues have been a stumbling block. Hamstring issues have held him back to just 24 appearances this season.
But in his brief moments of fitness and excellence he has obviously impressed at the club - as they are reportedly set to take a chance on him again next season.
It is reported that the club are willing to offer Chelsea another loan deal for the player next season - when they will hope he can remain fit and have a more sustained and prominent effect on the first-team affairs.
Now Marin has spoken about his future - indicating that he could still return to Stamford Bridge. He told the German Press Agency:
“My future is still undecided. We’ll sit down after the season and talk about my situation. Sevilla wants me to stay here, but there are signs from England that they want me back. I’m flattered and proud that they want me to stay here. The fans are quickly earn the hearts of the players.”
It is hard to see him returning to Chelsea but he seems to believe they want him back. With Willian, Mohamed Salah, Andre Schurrle and Eden Hazard for competition you can see why it seems strange that Chelsea would even want him back.
Soon enough we will know where Marin’s future lies.