They moved into the Champions League quarter-finals with an emphatic 4-0 aggregate success against Borussia Moenchengladbach in midweek.
But as the quadruple talk intensifies, Guardiola is keen to stop his players losing focus.
Guardiola was quick to rebuke his defender for getting ahead of himself and, aware how tough it is to challenge in so many competitions, City midfielder De Bruyne agrees.
City won the domestic treble in 2019, but missed out on Champions League glory after losing to Tottenham in the quarter-finals.
“I remember people two years ago were saying that we could win it, but it’s very hard,” De Bruyne said after his superb goal in City’s victory against Moenchengladbach on Tuesday.
“The amount of games and the physical and mental ability you need to have as a player or as a squad is very high. We try to do our best and focus game by game. That is the only thing we can do.”