Green told The Sun: "When he first came training with the lads he was an unknown quantity but you could see he was sharp in and around the box. His quick feet was a real eye opener for some of the boys. To see somebody with that sharpness had come through so young.
"He looks really good. He's a quiet lad but he's got that confidence about him that when he gets in the box and gets a chance he'll take it. That's what he did against Blackburn and he was within a width of a post away from scoring against Everton.
"It's up to the club and people close to him to keep his feet on the ground these first few years. You see too many young lads who burst onto the scene, particularly those who play up front, who end up trailing away into the lower leagues. But I'm sure we'll look after him."