Former Borussia Dortmund physiotherapist Frank Zollner has admitted Liverpool boss Jurgen Klopp can go “pretty crazy” sometimes, but he always “had the balls” to apologise to people if he went too far.
Zollner is considered a legend at Signal Iduna Park, having worked for Dortmund for almost 20 years between 1992 and 2009, but is now a part of the backroom team at 2. Bundesliga side VfL Bochum.
During Zollner's time with BVB, the club won three Bundesliga titles and the Champions League and naturally the 52-year-old has plenty of stories to tell when it comes to head coaches he worked under.