It's hard to believe Pep Guardiola hasn't won the Champions League for nine years. It's the most difficult challenge in club football – no manager has ever lifted more than three European Cups – but the long wait will still rankle for the greatest coach of his generation.
The Guardiola triumphs of 2009 and 2011 were near the beginning of his managerial career when he built an iconic Barcelona team that included Lionel Messi and the midfield pair Xavi and Andres Iniesta whose chemistry made it impossible to mention one without the other.
Since then, he has tried and failed with Bayern Munich and Manchester City, not going beyond the semi-final. Despite the City fans disliking UEFA, the club hierarchy crave the Champions League. It took Roman Abramovich nine years to reach the summit after he bought Chelsea but City's Abu Dhabi owners are still waiting 12 years on.
Pep Guardiola's nine-year Champions League drought will rankle for the acclaimed Spaniard
His Manchester City side were stunned by Lyon in a 3-1 defeat at last year's quarter-final stage
The club hierarchy crave Europe's greatest prize but are still waiting after 12 years at the Etihad
As the club return to European competition on Wednesday night against Porto, only two months after their dismal 3-1 defeat against Lyon in the last season's one-off quarter-final, Guardiola is taking the failure personally.
'I felt so responsible,' he admits. 'It was a tough moment. I was not able to drive the club and players. We have to accept the reality, we were not good enough.
'We didn't play badly, but we made mistakes and can't do that in this competition. Every player and manager has to dream but we have to accept (defeat) with humility.'
Guardiola's status is assured. Nobody can match the 100 points City reached in the 2018 Premier League nor the domestic clean sweep of Premier League, FA Cup and League Cup the following season. But this perfectionist will feel something is missing until he brings the Champions League to the Etihad.
Guardiola took responsibility for the Lyon defeat and admitted he could not 'drive the players'
His desperation for the trophy is altering his thinking and has caused him to tinker in big games
The common perception is that Guardiola is too stubborn to abandon his free-flowing philosophy for the pragmatic tests of Europe.
That may have been the case during his time at Bayern Munich when he reached the semi-finals three seasons in a row before conceding five to Real Madrid, five to Barcelona and then losing to Atletico Madrid on penalties, but at City he may have suffered the opposite problem.
There seems to be a tendency to over-think matches rather than trusting his instinct.
'That squad can win it if Pep stops thinking he is Clark Kent,' one source told Sportsmail last season in relation to Guardiola's