Sometimes there is no need to say anything.
When you are as expressive on the touchline as Pep Guardiola, visual evidence can be enough to gauge the importance of an occasion.
In Tuesday's 2-1 victory over Aston Villa, there was a long period of simmering discontent, then thinly disguised fury at the penalty given against his team after referee Craig Pawson had been told to stop the game to check Ruben Dias' 'foul' on Jacob Ramsey.
Most thought video assistant referee (VAR) John Brooks was right. Guardiola was not among them. He shook his head, ranted at his coaches on the bench, then launched a tirade towards the nearby fourth official.