Lapadula coming only would make sense if Morata stays. Go all in on Morata (25m-30m) and in order to make up for it sell Zaza to some mediocre PL team (20m-25m) and replace him with Lapadula as back up (7m-8m), then a year later sell Lapadula to a mediocre PL team for 15m-20m. 

