Barcelona head coach Gerardo Martino was frustrated with the way Atletico Madrid stopped his side from finding its rhythm in Wednesday's Champions League defeat.
An early goal from Koke sent Diego Simeone's side into the semifinals with a 2-1 aggregate win, as Barca failed to capitalize on clear-cut chances for Lionel Messi in the first half.
Martino - who has failed to beat Atletico in five meetings in all competitions this season - feels more ruthlessness in front of goal could have swung the tie in his team's favor, but admits the Blaugrana struggled to settle into their usual style against a spirited home side.
"Results happen for a reason. When Atletico were the better side, they scored their goal. We also had opportunities and just one goal from us would have changed the course of the game," he is quoted as saying by UEFA.com.
"At certain points, we couldn't do the things [we wanted] because of how our opponents played. Atletico kept a lot of players near their penalty area – they did that very well and that made it hard for us to find any space.
"This environment [the home fans at the Vicente Calderon] is difficult to find in Europe, but it's more common in Argentina. We have to keep fighting in the two competitions that remain for us now: the league and the Copa del Rey."