As a person, Christian is someone who at first you might say is kind of a bit timid, but when you get to know him well, he really opens up.
He is a very caring guy, who looks out for people, but he’s also someone who I’ve always had a really good laugh with. We hit it off straight away.
It was the same on the pitch. Straightaway, I loved playing with him at Chelsea. We had a great understanding and our games complimented each other so well.
I played as a target man and I needed some pace and movement around me – someone like him playing in the pocket between the lines and getting on the ball, looking for me and feeding off my flick-ons. Christian reminded me of Eden Hazard, with the way he took on opponents and found it easy to dribble past people.
He had so much talent, he just needed a nice environment around him – a good atmosphere in the team and also he needs to be loved, and appreciated, for him to be confident and play with freedom.
That was the difference between him and Eden – the way Eden was, he just played football for fun and he did not question himself too much. He was so relaxed while, sometimes, I felt like Christian was putting too much pressure on himself. He had too many things in his head.
It meant he played within himself sometimes for Chelsea, not expressing his talent, but it was different when he joined me at Milan in 2023. I said to the boys that he was going to be a proper plus for the team and he seemed to elevate his game and play with that confidence he needed.
He grew in Italy because he got older and got more experience. It was good for him at first to play in the Premier League against tough teams and tough defenders, and then also he has learned from being in Serie A where as an attacker you face some teams who, tactically, are just focused on you.
When Milan played with Rafael Leao, Christian and myself up front, we complimented each other a lot, and that is the kind of cohesion the United States will need too.
Christian needs his team-mates because he cannot do it all on his own – but if he has got the right players, he can bring them with him because he has got the experience and the quality to carry the team.
It was important that he ended his goal drought against Senegal at the end of May because it gave him some confidence to take into the World Cup too. No-one is expecting the USA to win this World Cup, but if they are going to reach the knockout stage, he will be key.
I have always thought the USA are lucky to have him, because he has skill AND intelligence. Talent on its own is not enough and, if you are not focused like he is, you won’t achieve amazing things. I wish him nothing but the best.
Olivier Giroud was speaking to BBC Sport’s Chris Bevan
