De Jong is a £7 million target for the Nerazzurri.
Sneidjer said: "De Jong is bravissimo. 'I've known him for seven years, we have grown together and I can assure you that he is crazy - in a good way - for football.
"If a match is at half-eight in the evening, he wakes up at eight in the morning and spends the whole day thinking only about how to win and give his best.
"On the pitch he always plays with heart and if he came to (Inter) Milan it would be a pleasure for me."