FCM won 1-0 thanks to an 80th minute Cho Gue-sung header.
Pereira said afterwards: “The ball didn’t want to obey and go inside the goal. Every time someone was in front of the ball or we had the goalkeeper or a player in front.
“But we tried. We had 22 or 23 shots. It is football, they created two chances and scored a goal.
“But we still have time. They (Midtjylland) are celebrating a lot. It was like they finished the game today, but it is not finished.
“Now it is time to recover mentally and physically and be ready for Fulham (in the Premier League on Sunday), because that will be another challenge for us and another tough game. After that, we will see what we do in the second game.
“Sometimes you can produce, you can play and you can create chances, but in the end I cannot say to my players they didn’t do everything to win the game, because they did it. They tried everything to score a goal.
“A defeat is football. It is a cruel, difficult day. But it is important to keep the spirit and the mentality, and to recover to play the next game.
“The players are frustrated, of course. But I am proud of them, because they tried everything with the spirit I want to see and with quality. With the rain, creating a lot of chances to score was not easy.
“We didn’t concede a lot to this team. I only remember them having two chances in the game.
“I’m proud of our supporters because they believed from the first minute until the end and they tried to help the team. It is half-time and we will see what we can do in the next game.”