Antonio Conte said hero-turn-villain Daniele De Rossi was aware of his mistake in retaliating in Italy's 1-0 win over Bulgaria on Sunday.
While the victory took the Italians closer to sewing up their spot at the Euro 2016 finals in France, Conte said De Rossi's dismissal was due to an error in judgement from the Roma midfielder - as he kicked out at Bulgaria's Iliyan Mitsanski for a crude challenge, the pair both seeing red.
Conte - an eight-time Serie A winner as player and coach with Juventus - said goalscorer De Rossi, who netted an early penalty, should have known better than to retaliate.
"Honestly I didn't see the incident, but if he did react then obviously he was in the wrong. It's very, very simple," Conte told a news conference.
"I didn't see what happened, but if he did react then he committed a mistake because he could have compromised everything and that cannot happen.
"Again, though, I didn't see what happened, but I think that he knows what he did was wrong and there is very little to say about it."
Conte rued Italy's profligacy, with Graziano Pelle coming close to scoring twice, while Mattia De Sciglio had a half-volley kept out by Bulgaria goalkeeper Bozhidar Mitrev.
"Well I think that this is a match which is fairly simple to analyse," Conte said.
"We created many chances, but we weren't able take advantage of them.
"Obviously this allowed the game to be completely open up until the end and in turn we became slightly apprehensive, because this result was very important for us… especially after what happened in the game between Norway and Croatia, with Norway winning 2-0.
"At the start many proclaimed ours to be an easy group, but I think they were proven wrong.
"Actually this might even be the hardest group there is, as Croatia - who many said was the best team in the group - is starting to realise now.
"So now there is still a tough road ahead of us and we will need to fight if we want to qualify, which is still anything but certain at this point."
