The giant striker asked for help in adapting to the different style of football after his summer transfer from Aston Villa.
He is facing a late fitness test before Belgium’s Euro 2016 qualifying clash in Cyprus on Sunday, and then a huge date for his club at Manchester United this Saturday.
And, with just one Premier League goal so far this season – and that one should have been ruled out for offside – the 24-year-old knows he is under pressure to start justifying his huge fee.
Michel Bruyninckx, the specialist coach credited with the development of Belgium’s current crop of world stars, revealed: “One day, he gave me a call and said, ‘Can I have some additional sessions.’
“When he was a boy in Belgium, he changed regularly from one club to another, because he only had one profile — as a physically strong player. I tried to encourage him then to expand his mind to see that he must not accept those labels and that he could continuously change his skills, and the way he learned to think has been enormously important to his career.
“I hear people say he is not a Liverpool type of player, but I tell you that he can adapt to any club.”
Bruyninckx, 64, built his reputation at Standard Liege and with Belgium's age-group teams and now works worldwide, advising clubs such as Real Madrid and AC Milan on how to expand the football intelligence of young players.
He said: “This challenge is not new for him. For many years, people tried to convince Christian he was only a physical player, but, through his mental power, he has changed all that.
“When you watch him in the national team, you can see that, technically, he is skilled, he is creative, he is intelligent. I fully believe that, through Liverpool, he will go to a higher level again.
“Even back to when he was in the same Belgium Under-17 team as Eden Hazard, most of the coaches looked at him only as a tall, physical player and said that he didn’t have the same technical ability to progress that Hazard was showing.
“But, step by step, he has understood that the modern game requires other things and his mental endurance and mental power has changed a lot.
“When I spoke with him, when he gave me the call, I said, 'Listen, Christian, you have to work on it, and that will open your world. If you decide yourself, then you can go to anything.'
“One of his major points is that he has a broad mindset. He is open to learn every day of his life.
“We understand, more and more, that the capacity of the brain is remarkable and, once a player is aware how the game is played in the head, he can evolve continuously.”