Macari wrote in The Sentinel: "If youngsters become wealthy overnight by signing a contract at 18 or 19, then not all of them will still have the hunger to work at their game.
"I say 'could' because the fee will depend on Powell achieving his full potential ... and I assume there is a clause in his contract about him going on to play for England.
"But that will depend on the player himself. He'll get great coaching at United and train with quality players, but in the end it will be up to him.
"I hope he makes it because, sadly, too many players fail to develop once they sign their first big contract."