Manchester City face Bundesliga side Schalke in the first leg of their Champions League last-16 tie on Wednesday, aiming to win the competition for the first time.
They play Chelsea in the Carabao Cup final on Sunday and are top of the Premier League on goal difference.
“The goal is not to win the four, it is to win every game,” said De Bruyne.
“You cannot set the standards to win four trophies. We are happy where we are – we want to progress in every competition we play in. To win all four, that is nearly impossible.”
Pep Guardiola’s side ran away with the league last season with a record 100-point tally and hammered Arsenal 3-0 in the final to win the Carabao Cup.
But they suffered a shock fifth-round defeat to Wigan in the FA Cup and lost both legs of their Champions League quarter-final against Liverpool.
On Saturday, English midfielder Phil Foden said City can “definitely” win a historic quadruple this term.
Asked how City compare to last season, Belgium international De Bruyne said: “I think it is the same. We are still fighting on all fronts.
“Other teams figure out what we do and have better squads. We always play the same under Pep, there is not a lot of difference to last season.
“The standard is very high, but maybe we win more this year.”