Fabio Capello believes a "traumatic" changeover following the departure of Carlo Ancelotti hindered Rafael Benitez's chances of succeeding at Real Madrid.
Benitez lasted just seven months as Madrid boss, sacked in January with the club sitting third in La Liga, behind Atletico Madrid and Barcelona.
Asked why things did not work out for Benitez, Capello told AS: "I don't know. You'd have to be in the dressing room.
"If there is no rapport with the coach it's difficult to succeed. Benítez has experience.
"It is possible the changeover from Ancelotti to Benítez was too traumatic."
Zinedine Zidane was chosen as the man to replace Benitez and has guided the club to three wins from four league fixtures, Madrid scoring 17 goals in the process.
The French legend became Madrid's 13th coach since the beginning of the 2003-04 season and Capello has his concerns.
"That's a lot. A lot," he added. "I don't know. Madrid is a very tricky club. If the president goes over the coach's head to talk directly to the players about problems in the dressing room, the coach is finished and the players know it.
"They say to each other: 'The president asked me why this happened...', and then they think that the coach isn't relevant."