Eusebio Sacristan felt the early goal Real Sociedad conceded to Atletico Madrid was decisive in the 3-0 defeat.
Diego Reyes put into his own net after seven minutes and Saul Niguez shortly after half time and Antoine Griezmann on the hour settled the tie in favour of Los Colchoneros.
“We conceded an early goal, we made a mistake for which we were punished a lot,” Eusebio said post-match, AS reports.
“The plan was to play a long game, weathering, control Atletico on the inside, but that was soon truncated.
“In the second half we wanted to go out with pace, but we conceded again quickly.”
Eusebio explained that a desire to avoid over-burdening his players was at the root of the host of changes he made from Saturday’s draw with Malaga.
“There were people who were accused of being tired the other day. We wanted to freshen up but it cost us,” he continued.
“We didn’t manage to close their game inside, where they are very powerful. Atletico are very strong, clear on how they play.”