Manuel Pellegrini has said Real Madrid directors intervened in team selection during his time with the club, who are reportedly considering Liverpool's Jurgen Klopp as a successor to Zinedine Zidane.
Pellegrini, now at West Ham, was appointed as Madrid coach in summer 2009 but sacked after a season in which they suffered a surprise Champions League exit to Lyon.
News agency EFE reported former Villarreal and Manchester City manager Pellegrini as saying he had refused to follow instructions on team selection from the Bernabeu hierarchy.
"One of the discussions I had with the Real Madrid directors was about the performance of the players," he said. "They told me that some had to play no matter what, but I never tolerated that."
Some reports have claimed Zidane stepped down last week because of a disagreement with president Florentino Perez over squad planning for next season.
Speaking from the France camp ahead of the World Cup, Madrid defender Raphael Varane said Zidane's successor would find it tough to replicate his achievements.
"We need a coach able to coach within the merengue [a type of dance] context," Varane said.
"Zizou did something exceptional which will be difficult to repeat. We cannot ask the new coach to be the same as him. He must have experience. Zizou did not have it as a coach, but he did on the pitch."
Following Zidane's departure, Madrid were linked with Tottenham manager Mauricio Pochettino, Juventus coach Massimiliano Allegri and Germany's Joachim Low, but now Marca has reported that Klopp, whose Liverpool side lost to Madrid in the Champions League final, is the most likely contender.
Current youth team coach Guti, a former Madrid player, has backers among his ex-teammates, while AS has added ex-Real midfielder Michel to the list.
Long-time Madrid defender Fernando Hierro, currently sporting director with the Spain national team, is also reportedly in the frame.