Mateo Kovacic helped out Havertz a lot when he joined Chelsea.
The German playmaker joined the Blues last summer in a £71m deal from Bayer Leverkusen.
In a recent interview, he opens up about how he hit it off with Kovacic the moment he arrived at Stamford Bridge.
Kai said: “One of the players that helps me a lot for example was Kova. I had from day one a very good relationship with him.
“He’s a different character of playing football. But I think we share the same understanding of football.
“Before the game, a very calm person and for me this is good sometimes to be next to somebody that is very calm.”
He added: “He is like a hero because he always wants the ball. Even when maybe we concede a goal he is always the first one to take the ball and in doing that he gives us a lot of confidence.
“He is very young and won three Champions League titles. He is a player that likes a lot of movement, is quick on the ball. It’s good for a team like us. It’s good to have someone like him at Chelsea.”