AC Milan looked to be in control of their Champions League destiny at home to Feyenoord on Tuesday before the sending off of Theo Hernandez turned the playoff on its head although coach Sergio Conceicao 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 last 16 with a 2-1 win overall.

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," Conceicao 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 Conceicao 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," Conceicao said.

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

Conceicao 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."

Meanwhile, Feyenoord interim boss Pascal Bosschaart was full of praise for his team's character, after recent upheaval at the club, when they came back from conceding an early goal to draw at AC Milan on Tuesday and reach the Champions League last 16.

The Dutch club's preparations for last week's first leg were far from ideal when Feyenoord sacked Brian Priske two days before the playoff game, but Bosschaart led them to a 1-0 win at home and they finished off the job at the San Siro.

"This says about the team that they have character. I think that's what I'm most proud of," Bosschaart told Ziggo Sport.

"You have to remember that they come from a very difficult phase, have received a lot of criticism, a change of coach, and then an unknown person comes in front of the group who occasionally throws in some empty slogans.

"That is a very difficult phase for them but I do think we are very clear, very transparent and very honest and this group responds very well to it, so I am proud of it."

Bosschaart's side could not have had a worse start in Milan, when former player Santiago Gimenez put the hosts ahead in the opening minute, but they fought back in the second half, after Milan had Theo Hernandez sent off.

"If you concede a goal within minutes, the plan you wanted to execute will be different again," Bosschaart said.

"Everyone will now say that we took the upper hand after the red card but I also thought in the first half that we played quite well. Only after the red card it might be a little easier."

Feyenoord could return to the San Siro in the next round, where they will face either Inter Milan or Arsenal, but for now Bosschaart needs to let their achievement sink in.

"It's beautiful. We are one round further, so very special," Bosschaart said.

"It's fantastic but I have to say, it hasn't really landed with me yet."