Chelsea defender Ian Maatsen had a very productive loan spell at Borussia Dortmund. There, Ian Maatsen made 23 appearances and came up with five goal contributions. It comes after the defender only managed to make one league start at Chelsea during the current campaign before his loan move to Borussia Dortmund back in January. However, while Maatsen’s loan to the German club was a good one overall, it did not end well for the left-back. Maatsen and Dortmund lost 2-0 to Real Madrid in the Champions League final on Saturday evening, with the Dutchman making a very costly error during the game. C…