Estudiantes coach Leonardo Astrada resigned on Wednesday to become the fourth coaching victim since the Argentine season resumed one month ago.
Astrada, in charge since last September, quit a day after a 1-0 defeat away to Ecuadorean champions Deportivo Quito in the Libertadores Cup.
"The poor results in the last few games and the fact that the team were not working collectively were the key points in his resignation," the club said on their website.
Estudiantes are third in Libertadores Group Five with three points from three games and have taken four points from five games in the Argentine Clausura championship.
Omar Labruna resigned at Gimnasia-Jujuy two days ago while Racing Club and Rosario Central have also changed coaches since the mid-season break.