The 23-year-old Sunderland winger expressed his disappointment at remaining on the substitutes' bench throughout the 2-1 win over Kazakhstan on Friday night, describing the situation as a "f****n* joke".
Trapattoni, who decided to retain McClean for tomorrow's friendly against Oman after he issued a personal apology to the entire squad, admits that the player would have been axed had he have been representing a bigger footballing nation.
"Another manager, English or German, would have said 'take your bag and go home', but I might need him in the game to score a goal," said the Italian. "He was mortified [when he was pulled up in front of the squad].
"If he could have, he would have eaten his words. He was very apologetic. I said to everyone this is not about respect for the manager, this is about respect for everyone. I said the players are your colleagues.
"If I don't play him, I can play others. There was Stephen Kelly and Kevin Doyle on the bench. They have many caps. The matter is closed now. With the young we need to have patience. Sometimes they say things they regret."
McClean has been capped four times at senior international level.