Pep Guardiola knew what the referee was like. It was the same referee who he blamed for his side’s exit to Monaco in last season’s Champions League. Yet despite being fully prepared for Antonio Mateu Lahoz, he still allowed himself to get emotional. It cost Manchester City dearly.

One thing that footballers do – and we’re all guilty of it – is to look for an excuse. By getting sent off against Liverpool with his side in the ascendancy, Guardiola gave his players exactly that: a ready-made excuse. Even though he was right to be aggrieved by Leroy Sane’s disallowed goal, his behaviour sapped his side of their momentum. It wasn’t Mohamed Salah’s goal that ended City’s hopes of progress. No, their challenge faded when Guardiola lost it with the referee.

If you’re in a war and your commander is running towards the enemy, only to suddenly divert his attention to something else, you’re going to think ‘oh, we should do that too’. Bang. You’re in trouble. It’s the manager who is leading the players and Guardiola’s reaction led to his players losing their heads in the second half. You have to hold your emotions in football; you can’t allow them to step in front of you if you want to succeed. Guardiola has to take responsibility for that.
He needs to return to some old-school management: forget the glossy football for a moment and tell his players that if it isn’t going right on the pitch, they have to dig deep and keep their discipline. They haven’t done that in the last two games. They allowed Ander Herrera to rile them with his constant diving and overreaction during the Manchester derby comeback; they allowed a refereeing error to influence their performance on Tuesday night.

City were looking at the Treble, but they’ve allowed emotion to cost them a shot at the Champions League semi-finals. Guardiola will look at his team, and those left in the competition, and think ‘it was there for the taking’. And perhaps it was. But his actions mean we will never know for sure.