'Are you crazy?': Mainz fans slam Klopp's Red Bull move

Using a play on words with Klopp's last name, the home fans asked "Are you crazy?" and used a quote from their side's former boss: "I like people until the point they disappoint me." A larger banner, in big red letters, asked Klopp if he had "forgotten everything we gave you?". A former player at the club, Klopp coached Mainz for seven years, taking the team to the top flight for the first time before moving to Borussia Dortmund and later Liverpool. Klopp stepped down as Liverpool manager in the summer having won several titles...