Former Schalke assistant coach Sven Hubscher is in regular contact with Liverpool defender Josip Matip.
Matip left S04 three years ago for the Reds and has told Hubscher about life under Jurgen Klopp.
"Klopp is very emotional and it is transferred to the players. Everyone is ready to go with gas full. Competition also plays an important role, which facilitates the coach's work," he told Goal.com.
"Still, he (Matip) says that everyone is ready at any time to march as soldiers for Klopp. He has never had a harder preseason in his life than in Liverpool. How fit the team is can be seen on the pitch.
"They play with a chain of four in defence, in front of them run three maniacs from right to left and in front of it they have three grenades that do the damage. That's how they won the Champions League last season."