Manchester City have "peaked" under Pep Guardiola, according to Dietmar Hamann, who thinks "any other manager would be in big bother" if they had failed as often on the European stage.
Guardiola's nine-year wait for success in the Champions League was extended after City suffered a shock quarter-final defeat at the hands of Lyon last season.
The Spanish boss has not won the competition since leaving Barcelona, having also fallen short at Bayern Munich, with supporters at Etihad Stadium growing increasingly impatient with each passing year.
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Guardiola has delivered eight trophies during his four-year stay in Manchester, including two Premier League titles, but a lack of success in Europe's elite competition is now beginning to threaten his legacy.