Former Everton fitness coach Jan Kluitenberg is delighted seeing Dominic Calvert-Lewin fulfilling his potential.
Kluitenberg was part of former manager Ronald Koeman's backroom team at Everton.
He told the Liverpool Echo: "There were other young boys too but Calvert-Lewin, at that time, he was already an athlete. But he needed training hours, hours in the gym, to create, more or less, a new athlete for the Premier League.
"It's easy to say now, but at that time I saw a guy who could maybe be the No9 for England in the future. I try to watch a lot of matches now and he is strong and he is fast and in the box, he is always looking for the goal.
"At that time, he knew already that he had to invest in himself and he will be a very good striker in the future."
