Manchester United will have to part with £16.5m to secure the services of Villarreal's Mateo Musacchio, according to the defender's agent.
The 23-year-old, who has two caps for Argentina, has been one of the best defenders in La Liga this season.
It is believed that his form has attracted interest from the Premier League champions, but Villarreal will demand a premium sum for his services.
"The player's contract expires in 2018 and his market value is approximately £16.5m," his agent told 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."
Musacchio joined Villarreal from River Plate in 2009.