Former Real Madrid boss Vanderlei Luxemburgo has backed Zinedine Zidane to be a success at the Santiago Bernabeu - providing he is not undermined by Cristiano Ronaldo.
Luxemburgo spent an 11-month spell at Madrid in 2005 as part of a nomadic career spent mostly in his native Brazil.
And he is confident former France midfielder Zidane will succeed but believes he needs the backing of influential striker Ronaldo.
Luxemburgo told Omnisport: "Zidane was a leader in the dressing room when he was a player, so Cristiano Ronaldo will have to understand that there will be a person with leadership and with great knowledge of football there.
"The dressing room belongs to the players up to a certain point. From then on it belongs to the coach. If Cristiano Ronaldo thinks he's the coach it's difficult. He has to understand he's a player and not a coach. The coach is Zidane.
"If you can make those things clear it doesn't matter if it's Cristiano Ronaldo or [Lionel] Messi. Barcelona is giving a good example that Messi is just a player. He was a player with [Pep] Guardiola and is still a player with Luis Enrique. He's a star but is still a player. That's his limit."
Luxemburgo also suggested Madrid president Florentino Perez needed to give Zidane full control over dressing room affairs.
"If it was another president things would probably not have gone this wrong," he added. "Luis Enrique was questioned when he left Neymar on the bench. But he left him on the bench to adapt. At Real Madrid, if the coach leaves Ronaldo on the bench, Florentino Perez goes crazy.
"There's a big difference between Real Madrid and Barcelona in that respect. The head coach at Barcelona is in charge. At Madrid, it's not like that with Perez."
Luxemburgo coached Zidane during his brief spell in the Spanish capital and was impressed then with the midfielder's leadership qualities.
"It's not a surprise because Zidane was being prepared to be Real Madrid's head coach," he said. "The surprise is the moment he took charge, that he came now and not later. But he's a high-level professional with a great knowledge of football.
"When he used to be a player and I coached Real, I used to pass him a lot of information and then he transmitted it to the group. He was like a coach on the pitch. So I think he has everything to do a great job. He has leadership, he knows the club and all that helps."
