The Italy defender was shown a red card towards the end of Sunday's Milan derby for vehemently protesting referee Emidio Morganti's decision to wave play-on after Adriano appeared to be elbowed inside the penalty area.

But Mourinho thought the decision was harsh on Materazzi, who was sat on the bench at the time of the incident having already been substituted.

"I am sorry because he is a great boy, is very professional and I think he is a player who is not respected in football like he should be," said the Inter coach.

"It is just too easy to show a card to Materazzi.

"I knew about this scenario for a long time before coming here, but I don't understand it very well."

Materazzi may be treated like a hero when he pulls on an Italy shirt, but, following his clash with Zinedine Zidane in the 2006 World Cup final, he has to listen to a whole manner of insults from opposition fans when he wears the blue and black of Inter.

That was again the case at the San Siro on Sunday night as the Milan fans targeted him for abuse, but Mourinho leapt to his defence.

"I don't know why every place we go, there has to be an offensive chant against him or his children," continued Mourinho.

"He is a boy who lost his mother as a child and I really don't know where all this is going to end up.

"There is not a single game away from home in which this boy is not under pressure."

Mourinho believes it is not only the fans who find him an easy target. He believes Materazzi is an easy target for referees too.

"He just reacted like all of us on the bench," said Mourinho.

"What he did, we all did, and who did the red card go to? Materazzi. There is such a lack of respect for this boy."

His dismissal, which came shortly after Nicolas Burdisso was given his marching orders, leaves Mourinho short of defenders for his side's next Serie A fixture at home to struggling Bologna on Saturday.

Sunday's 1-0 defeat by AC Milan means Inter trail league leaders Lazio by two points after five games of the season.