Marin came close to joining Spurs in January.
"Tottenham were interested in me in January but I decided early on that I wanted to come to Chelsea," he said.
"When Ballack moved to Chelsea everyone in Germany was interested in the club. Ballack was the biggest star in Germany at that time, the captain of the national team.
"But it's nice to have some Germans around me in London. I know [Lukas] Podolski and [Per] Mertesacker at Arsenal.
"But I don't know why there haven't been more Germans coming to England. In the last few years Germans have started to move to other countries.
"Now there are a lot of good young German players who are not afraid of taking the step to move to a different country."