Valencia are attempting to quell interest in forward Rodrigo Moreno by demanding potential suitors pay his full €120 million (£107m/$139m) release clause.
The Spain international, who appeared three times at the World Cup, has attracted interest after scoring 16 goals in La Liga last season.
European champions Real Madrid are rumoured to be considering an approach for the player they sold to Benfica in 2010.
Any deal would come at a nine-figure cost, though, with Valencia expecting to be well compensated for the 27-year-old.
"The plan is to start the season with Rodrigo," head coach Marcelino told reporters.
"The club has stated there is a release clause and anybody who wants to sign him will have to pay it. If a club comes in and the player wants to leave then there isn't much we can do.
"But I'm not thinking about that and I'm not going to concern myself too much with it because if it happens there is nothing we can do to change the situation."
Brazil-born Rodrigo made his senior debut for Spain in 2014 and has scored two international goals.