Osasuna have referred Manchester City to Nacho Monreal's buyout clause.
City boss Mark Hughes made a personal check on the Spain international left-back on Saturday in Osasuna's 1-1 draw with Barcelona.
Asked about the presence of Hughes, Osasuna president Patxi Izco said: "We are counting on him (Monreal), we will only begin talking with interested clubs if they're prepared to pay his (buyout) clause."
Monreal's clause is set at £12 million.