David Moyes is keen to rebuild his defence, with both Rio Ferdinand and Nemanja Vidic out of contract with the champions in June.
Argentine centre back Musacchio has been one of the standout defenders in La Liga this season, and has previously been linked with Liverpool.
And now the player’s agent has revealed the figure United would have to pay for his services, while also warning they face a fight with Italian giants Fiorentina to land the highly rated 23-year-old.
“The player’s contract expires in 2018 and his market value is approximately £16.5m,” he is quoted as saying in Marca. “He is a very young player. For now it will be difficult to transfer him.
“The player would be interested in projects like Fiorentina, but we are waiting for concrete proposals in the future. We do not have any kind of scheduled meeting with their officials.
“In June we will see. He is very attached to [former Villarreal players] Gonzalo Rodriguez and Borja Valero and often maintains contact. The club Fiorentina is growing. I think my client would be fine with a coach like Vincenzo Montella.”