Guardiola said he has very rarely complained about referees' decisions when City have lost big games but explained he has felt obliged to speak out in the face of a wave of controversial calls that have gone against his side, such as Dean Henderson not being sent off for handball in last season's FA Cup final or Antoine Semenyo's goal being ruled out against Newcastle in the Carabao Cup.
He said: "The FA Cup final, the position of the referee and the goalkeeper for Crystal Palace. It was a natural position with the hands? Look at my comments after the game. Never, ever, in 10 years have I criticised the referees. What I’m saying this season is arguments and reasons why we have done it.
"I defend my club and my players. Howard Webb defends the referees. He has to do that. Look what happens in the boxes from corners and free kicks: every action, it is not easy. Every action is a foul. Every action. I know it is not easy. But I have to defend my club and my players for many reasons.
"When we lose in the Champions League? (Chuckles) In the Champions League, Premier League, FA Cup – the first statement is congratulating the opponent all the time. All the time. I do it because I believe it is fair enough to say. But when you say one times or two times over 10 years that I am the type (to complain) then OK it’s fine, everyone defends his position.
"You defend when you work, right? I defend my club and players for what happened many, many (times). When you are six minutes for a disallowed goal in the Carabao Cup, I have to tell him you know. The hands against Wolves, it happened, but then what happened at Crystal Palace and Chelsea? I have to tell."