Real Madrid have reportedly inserted a release clause of €500m (£438m) in the contract of Dani Ceballos, who completed his move from Real Betis earlier this week.
Los Blancos won the race for the 20-year-old, seeing off rumoured competition from arch rivals Barcelona to complete a £10.5m transfer.
According to Spanish publication AS, Madrid have moved to ward off any further interest from Barca by setting the midfielder's buyout clause at an eye-watering price.
Ceballos, recently named Player of the Tournament for his part in Spain's run to the final of U21 Euro 2017, was handed a six-year contract at the Bernabeu.
Madrid have also brought in another youngster in Theo Hernandez this summer, as they add to their La Liga and Champions League double-winning squad.
