Pierre-Emerick Aubameyang has been warned by Dortmund to sort out his future - so that they can land a replacement. Chelsea are among a number of clubs keen to land the 28-year-old Gabon striker. Dortmund want interested clubs to open the bidding so that they can negotiate a deal and move on to his successor. Dortmund CEO Hans-Joachim Watzke said: “We have told Auba: ‘If you want to move somewhere, and you have a club willing to meet our demands, then come to us and we’ll talk.’ “But this will only apply within a certain time window, which is slowly closing. “We would clearly need to get a replacement for him, which is difficult to impossible in any event.