Chelsea fullback Ian Maatsen is eager to sign permanently with Borussia Dortmund.
Maatsen joined BVB on-loan in January to the end of the season.
Sky Deutschland's Patrick Berger is reporting: "Ian Maatsen wants to leave Chelsea on a permanent deal in summer.
"According to our information Chelsea is already informed about his plan.
"The left-back (2 goals, 2 ass. for BVB) feels very comfortable in Dortmund and is keen to stay. Release clause: €35-40m."
