The Barcelona boss believes his side could have changed the course of the match with more care in front of goal following their Champions League exit to Diego Simeone's men
An early goal from Koke sent Diego Simeone's side into the semi-finals with a 2-1 aggregate win, as Barca failed to capitalise on a number of clear-cut chances 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 favour, 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."