Franck Kessie and Lucas Biglia were involved in a row on AC Milan's bench during the Inter defeat, angering coach Gennaro Gattuso.
AC Milan coach Gennaro Gattuso was fuming with the bench row between Franck Kessie and Lucas Biglia during Sunday's 3-2 defeat to Inter, warning them he would have got involved too had he seen the incident initially.
Lautaro Martinez's penalty ultimately proved decisive as Inter crept above Milan and moved up to third in the table, but Gattuso was angrier about something else entirely after the match.
Kessie had been withdrawn after 69 minutes and looked visibly irritated as he was replaced by Andrea Conti.
When Kessie headed back to the bench, Biglia appeared to say something to him and he reacted aggressively, requiring several team-mates to physically restrain him.
Both apologised to the media after the derby clash, but Gattuso remained unimpressed in his post-match news conference.
"It can be that a player makes a mistake," Gattuso told reporters. "In the next few days I'll talk to those involved, now I don't want to say anything.
"I cannot accept that, even if you are angry. We are not in pre-school.
"Luckily, I didn't see it, because if I had seen the incident I would have made a fool of myself and I would have thrown myself into the fray too."
Defeat to Inter ended Milan's five-match winning streak in Serie A.