Athletic Bilbao coach Joaquin Caparros admits they could lose young defender Fernando Amorebieta in the summer.
The centre-half has been linked with Real Madrid, Manchester United and Liverpool this season.
"Amorebieta is really happy here. He is a player that grows and matures every day in every respect. He is also a very young player and should be here for a long time with Athletic," said Caparros.
"Yes, it is clear that if a team comes forward with money, with €20-30 million on the table, and the player wants to leave, we cannot do anything."
