Jürgen Klopp was on Saturday criticized by fans of his former club Mainz for taking the position of Head of Global Soccer at energy drinks makers Red Bull from January onwards. Fans protested with a number of banners during the Bundesliga match against RB Leipzig, one of the clubs backed by Red Bull. Klopp played at Mainz for 11 years before coaching the team 2001-2008. “Have you forgotten everything we made you become?” one banner said. Another used a past Klopp quote: “I like people until they disappoint me.” There was also a banner asking “Are you crazy?” – a pun on his name by using the Ge…