United are expected to bid for the AC Milan attacker in January after the youngster's impressive opening weeks of the season.
His junior coach, Dionigi Donati, revealed to TMW: "He was phenomenal, in a year he scored 132 goals. At the age of six years of age he'd win games by himself. In 32 years as a coach I've never seen someone like that.
"The biggest clubs wanted him, but my dream was for him to play for Juventus. I called them about him. However, they rejected him, saying he was too small."