Manchester City manager Pep Guardiola defended his team's system despite a 4-2 defeat by reigning Premier League champions Leicester City.
City started with a back three, but after falling 2-0 behind after four minutes reverted to a four-man defence.
Guardiola said: "It is not about the system. We defended well with these players at the beginning of the season.
"Now we have to stand up and analyse what happened, especially mentally to encourage the players to step forward."
England striker Jamie Vardy scored a hat-trick in Leicester's stunning win to end his 10-game run without a Premier League goal.