Despite not officially announcing Enzo Maresca as of yet, it seems as if Chelsea are wasting no time in the transfer market elsewhere. The club have seemingly already decided the areas of the squad that need improving in order to succeed under Maresca, starting with a ball-playing goalkeeper. Neither Robert Sanchez, Djordje Petrovic or the returning Kepa Arrizabalaga are famed for their decision-making behind the defence, and change can be expected. FC Porto’s Diogo Costa was recently linked with a move to Chelsea, a 24-year-old who is expected to start for Portugal at the Euros. Other names h…