Manchester City assistant boss David Platt defended Roberto Mancini for entering the pitch after the 2-2 Champions League draw with Ajax to remonstrate with referee Peter Rasmussen. City's Sergio Aguero had a goal ruled out for offside before Mario Balotelli was denied an injury-time penalty.
Platt said: "I don't think he is the first manager to go on to the pitch. He wears his heart on his sleeve."
He added: "Why wouldn't the manager of a football club be frustrated? Why wouldn't we all be frustrated?"
The Italian also appeared to lose his cool as a cameraman followed him onto the pitch at the final whistle.
"Robbie has gone onto the pitch and spoken to the referee. As he comes back, he turns around and has a camera in front of his face for 30 yards.
"He turns around and says, in English, that basically it is enough now.
"People then want to start talking about what has happened and almost exaggerating the incident." said Platt.