"In my opinion, Klopp is the key to Mo's form," he told Sky Sports. "He is a motivator who wants to play attacking football at speed. That is exactly the type of football that Mo needs.
"I think he's taken him to another level."
The Swiss added: "It has been fantastic to see how he has grown because he is a very good person.
"He is always funny, smiling and open. You can make jokes with him. He is not in it for himself. He is part of the team and everyone liked him."