Sevilla president Jose Maria del Nido insists Geoffrey Kondogbia will only leave for his buyout clause.
The midfielder has been linked with Manchester United and Real Madrid this week.
"Kondogbia is not on the market," he told reporters. "But whoever wants him has to pay his 20m clause.
"But please, any team that tries to sign him - don't. We will consider it an attack.
"I've already reached an agreement with [third-party owner] Doyen and Kondogbia will not go this summer."
