The former Blancos player said the 18-year-old should stay at AC Milan but admits the offer from the Spanish capital may be too good to turn down
AC Milan goalkeeper Gianluigi Donnarumma cannot say no if Real Madrid are interested in signing him, according to Antonio Cassano.
Madrid are one of the clubs to be linked with Donnarumma after he rejected an offer to extend his Milan contract beyond 2018, the Serie A club claiming their offer was worth €50 million over five years.
The 18-year-old had fake money thrown at him by angry supporters during Italy's match against Denmark at the Euro Under-21 championship last week.