Around two decades ago, Jurgen Klopp faced Ralf Rangnick while in charge of Mainz 05. The two coaches weren't personal friends at the time but their coaching styles appeared to be similar.
Shortly after the contest, the latter called the former to ask him questions about one of his upcoming opponents.
The team in question had faced Klopp's Mainz outfit just days earlier and Rangnick was keen to pick his brain for information.
