Diego Simeone took the blame for Atletico's derby defeat to Real Madrid in LaLiga on Sunday morning (AEDT).
Atletico's 26-game unbeaten run in the league was ended after Casemiro's header and Jan Oblak's unfortunate own goal at the Estadio Alfredo Di Stefano.
Atletico coach Simeone accepted responsibility for the loss, although his side remain top of the table.
"The coach was wrong in his approach and in the search for the match," he told Movistar+, via AS.
"He tried to intervene to improve what he was seeing."
Atletico failed to register a single shot in the first half of a LaLiga game for the second time under Simeone.
Simeone said Madrid deserved praise for a performance that moved them to within three points of Atletico, who have also played one less game.
"The boys have been making a huge effort, the team had not lost for a long time and one day it would happen," he said.
"When a team is superior we must congratulate it. We came from a very important effort in the Champions League and something could turn everyone's head throughout the game."
Atletico face Cardassar in the Copa del Rey on Wednesday before hosting Elche three days later.