AC Milan looked to be in control of their Champions League destiny at home to Feyenoord on Tuesday before the sending off of Theo Hernández turned the playoff on its head although coach Sérgio Conceição refused to blame the defender for their exit.

Having lost the first leg 1-0, Milan were level on aggregate in the opening minute but after Hernandez picked up a second booking for simulation, Feyenoord equalised in the second half to draw 1-1 and reach the round 16 with a 2-1 aggregate win.

Milan could have avoided a playoff altogether with a win at Dinamo Zagreb in their final league phase game, but on that occasion they had Yunus Musah sent off and lost 2-1.

"It's definitely a failure, we wanted to get to the last 16. This match showed that we are stronger than the opponent and that it was the episodes that decided, like in Zagreb, sending off there, sending off here," Conceição told reporters.

"You could say that the referee [Szymon Marciniak] was too harsh, but we had to be stronger mentally. I'm the one responsible, not Theo. Then inside the locker room we'll see.

"Theo has given so much to Milan, I have made many mistakes in my career. Until Theo's red card, Feyenoord didn't know how to get to the goal. We are disappointed and angry."

Santiago Gimenez, Milan's recent signing from Feyenoord, had put the hosts ahead but Conceição took the Mexican forward off in the second half and the manager explained his decision.

"We had one less player. Then there was Santiago to manage, he had an adductor problem and he needs to be managed," Conceição said.

"I put João Félix up front who was fine to try and counter, but we were controlling the game anyway."

Goalscorer Gimenez backed his coach -- and teammate Hernández -- after the heartbreaking loss for a resurgent Milan.

"Today it happened to Theo, but it can happen to anyone," the Mexico international said. "As a team, we give him our full support. He always gives everything and is one of the best full-backs in the world."

Conceição replaced Paulo Fonseca as manager at the end of December, winning the Italian Super Cup in his opening games in charge, and feels he is not always judged fairly.

"I arrived a month and a half ago, but they make comparisons with coaches who had been here for years," he said.

"We won the only trophy we could win, we are in the semi-finals of the Coppa Italia and in the league, since I arrived, we have earned 14 points and (leaders) Napoli 15.

"It's not perfect. The atmosphere here at Milan is not the best and the sending off proves it. We have to work on this. Believe me, it's not easy, it's not easy."

Information from Reuters was used in this story.