What caused 'unique' tactical approach?

In a recent match against Arsenal, Manchester City adopted a unique defensive strategy after initially taking the lead. Coach Pep Guardiola, known for his usual 4-4-2 formation, shifted to a more defensive setup of 5-4-1 or even 5-5-0 as the game progressed. This tactical change was influenced by the team's fatigue, as it was their third game in just seven days. Understanding Guardiola's adaptability in tactics is crucial, as it highlights how even top teams must adjust their strategies based on player condition and match circumstances.