"I don't normally comment on refereeing decisions," he told Rai Sport. "If Doveri saw something, it's useless to protest. I can fault my players as far as effort and commitment goes but Milan were just the better team.
"Maxi Lopez's red card makes me very angry, my player cannot get himself sent off like that. You cannot make a gesture like that. It is not on to lose your concentration, the referee knows what he must do but we cannot let that affect us.
"Anyone can lose a game but we need to look at how it happened. Today it happened with us giving our all."
Sampdoria are currently 13th in the Serie A table.