De Jong, who left the Etihad for AC Milan in a £5million deal 13 months ago, is closer to his fellow Dutchman than most of the footballers he has met in his life.
He told the Daily Star: "Robin is one of the best centre-forwards in the world. We are friends and we grew up together.
"I've known him for a long time now and he works hard every day to improve. He is one of the most talented players I have ever seen.
"He has great technique and is strong with his right and left foot. Yes, he's the complete striker and for sure my favourite player."