AC Milan head coach Sinisa Mihajlovic declared himself "very angry" with referee Piero Giacomelli and his own team after he was sent off during Sunday's 2-0 Serie A loss at Sassuolo.
Goals from Alfred Duncan and Nicola Sansone ended Milan's 12-match unbeaten run and Mihajlovic's misery was compounded when he was dismissed for dissent.
Defeat leaves Milan in sixth place, nine points adrift of Roma, who occupy Serie A's final Champions League qualification place, and Mihajlovic could scarcely contain his fury.
"I am very angry with us and with the referee, but I don't want to talk about that," he told Mediaset Premium.
"We dominated the first half hour, but as often happens we failed to turn that pressure into a goal.
"We cannot keep creating four or five scoring opportunities only to concede the first shot on goal, especially on a corner routine we knew they were going to use.
"Carlos Bacca was meant to come out and close Duncan down, but he did it too late. He should've been on the edge of the box. This happens when you don't have the right concentration."
Mihajlovic insisted his dismissal for dissent was undeserved, with the coach claiming he only swore at the referee after he had already been sent to the stands.
"I complained and the referee sent me off, so at that point I told him where to go," the Serbian said.
"But I only swore at him after the dismissal. I asked him how it was possible he hadn't seen that foul.
"Sassuolo did well to continue, I always tell my players to not stop until the referee blows the whistle. I don't want to talk about it."