Bayer Leverkusen coach Peter Bosz is backing Christian Pulisic for success at Chelsea.

Bosz worked with Pulisic at Borussia Dortmund.

He said, "I understand his move to Chelsea, the Premier League is different from the Bundesliga in the sense that you have to be physically stronger, but fortunately he is.

"Chelsea is not an easy club, because there are a lot of good players, but I think he has the qualities to succeed.

"He is a good boy and he is still very young. When I worked with him at Dortmund, he was young, but also very talented. He is fast and has a good shot. His mentality is also fantastic: he is a fighter and always works very hard. He is a good player."