At the end of the day, RM don't really need to sell Morata. Arsenal & United signed two of the few available top strikers out there, if Morata suddenly has a U-turn, after telling Costa he's surplus to requirements by text, this could be a messy window for the champions.
May even be forced to resort to the likes of Llorente etc.
RM don't need to sell Morata but he is desperate to leave. If anyone meets RM's asking price, he will leave.