Looking at how impressive Serhou Guirassy was last season, I think it was one of the major reasons Borussia Dortmund went for him which I think is a good move as they try to strengthen the team however, I don't see the club retain Sebastian Haller and Niklas Fullkrug alongside their new striker.
I agree that Serhou Guirassy showed an impressive very good performance last season and that Dortmund was very lucky as there was a few other Europe Top Clubs to get Guirassy.
Even i am a big fan about Füllkrug and Haller i guess that one of them will be leaving the Club.
Donyell Malen and Guirassy together can be very good combination for Dortmund to get fast forward on the field.