Pep Guardiola accused his much-changed Manchester City team of "playing safe" in their surprise Champions League loss to Bayer Leverkusen in midweek.
The City manager paid the price for making 10 changes to his starting lineup as the German side won 2-0 at the Etihad Stadium on Tuesday.
Guardiola felt his players were too risk-averse as they slipped to a second successive defeat following last week's Premier League reverse at Newcastle.
Referring to the Leverkusen defeat, he said: "We didn't try. In football, when you play on the green, you have to try things, and we didn't try."
He added: "I think they played not to make mistakes, not to play to do something, that is so difficult. In football, you have to play offensive, and you have to try... they played to be safe."
Guardiola, whose team face struggling Leeds on Saturday, suggested the players who started against Leverkusen had lacked confidence.
"I have a lot of confidence in them, still right now I have a lot," he said. "I have a huge value in what they are as football players, and that maybe is higher than (they have) themselves."
City are still without midfielder Rodri for the Leeds game, but Guardiola said the Spanish international would be back soon.
Guardiola's men are third in the Premier League table, seven points behind leaders Arsenal.