Explained: What Pep Guardiola's gross comments about Xabi Alonso 'peeing perfume' mean - as Man City boss prepares to meet his former player in Real Madrid clash

Guardiola has been seen as a mentor to Alonso, who achieved staggering success in his first managerial role at Bayer Leverkusen when he steered the side to an unbeaten Bundesliga title.