Ian Maatsen will spend the remainder of the season on loan at Borussia Dortmund and has signed a contract extension with Chelsea until 2026.
The 21-year-old has made 15 first-team appearances for the Blues this season but will now continue his development in the Bundesliga.
Maatsen joined Chelsea in 2015 from PSV Eindhoven and has previously embarked on loans at Charlton Athletic, Coventry City, and Burnley.
Good luck, Ian!