A problem with luggage in Germany meant the plane carrying the Leverkusen team had to return to the departure gate on Monday afternoon, delaying their arrival in Manchester.
A day later, City’s glut of alterations on matchday left one senior member of Bayer Leverkusen’s staff – in his own words – “shocked”, telling BBC Sport they had made due preparations for the contest but were not expecting that particular line-up.
Another staff member pointed to key players such as defender Edmond Tapsoba, former Real Madrid man Lucas Vazquez and Argentine duo Exequiel Palacios and Equi Fernandez being unavailable as a sign that they may struggle in the game, with six players from the under-19 side named on the bench.
Star man and goal machine Erling Haaland, Phil Foden and Rayan Cherki were all substitutes for City in the opening period and when later called upon they were ultimately unable to perform a rescue act in the second half.
Omar Marmoush failed to take his chance up front and attempted to rouse a home crowd that were often as flat as the team, while Savinho and Oscar Bobb were both on the periphery of the game.
City were slow, ponderous and the changes left them disjointed and this could end up being a damaging defeat in the competition – the loss means they head to European giants Real Madrid on 10 December under pressure to get some sort of result.
“They tried to do it [perform] but when you are in a big team you have to show off,” said Guardiola. “Everyone – [including] the guys who came from the bench – were the same. Every shot was blocked, they slipped 10 times.
“Maybe with the players who played regularly lately, maybe we would have had confidence. I always like to be too nice and involve everyone because I have the feeling after the international break there are games every three or four days hopefully and there is no human being can sustain that.”
Guardiola became just the third manager to take charge of 100 or more Champions League games for an English team after Sir Alex Ferguson and Arsene Wenger, but the landmark occasion was one to forget.
“The message from a lot of people will be, why didn’t you play a stronger team?” asked former City midfielder Michael Brown on BBC Radio 5 Live. “Win the game and then make the changes, that is what people will say.
“There was almost an expectation that it was just going to be routine but what it did do with those changes was give that away side a massive lift. If you’re walking on to the pitch looking across you’d be thinking we’ve got a great chance with all those players sat on the bench. That gave them the belief.
“That said, you still feel like the performance could have been a lot better from City with the players they had.”