Pep Guardiola is currently going through the worst season of a managerial career that had previously been almost flawless.
Even the best managers make mistakes occasionally though and Guardiola recently admitted to one that left him feeling regretful.
It was Guardiola's decision to allow a player to leave too soon that left him with regret.
However, Guardiola was not talking about City's decision to sell Cole Palmer to Chelsea for £42.5million in September last year.
Palmer has since delivered 34 goals and 17 assists in 52 Premier League games for his new team.