Jurgen Klopp and Matt Hummels spent four seasons together at Borussia Dortmund, a period through which they both won the Bundesliga title and a reached the Champions League final in 2013.
My relationship with Jurgen Klopp was unbelievably warm. But he was my boss. When he became our coach it wasn’t an issue that he hadn’t won any titles yet, nor played in the top flight,” Hummels told Bundesliga’s official website.
Hummels has since moved to Bayern Munchen while Klopp is at Liverpool.