The 24-year-old signed on for a season-long loan with the Primera Division outfit in the summer in search of regular playing time, with the German starting just two Premier League fixtures under former coach Rafael Benitez last term.
He told Perform: "We have to see how the second half of the season goes on and how I play.
"At the end of the season, or before, we will see. We will have talks with Chelsea and Sevilla, or with other clubs and see what happens.
"My first year at Chelsea, I did not play a lot or have many opportunities and I wanted to play again and that's why I left for a year.
Marin has failed to find the net for the Spanish outfit domestically this season, though has struck twice in the Europa League.