Paris - Zinedine Zidane needs to win trophies to survive as Real Madrid coach, and must win several of them to leave a heritage, former Liverpool boss Gerard Houllier told AFP on Thursday.
"At a top club you need to leave a trace, and to do that you need to win trophies," the Frenchman said, when asked what Zidane needed to do after he took over from sacked Rafael Benitez on Monday.
Houllier's own heyday came in the 2000-2001 season when striker Michael Owen fired Liverpool to five titles; the Community Shield, the League Cup, the FA Cup, the UEFA Cup and the European Super Cup.
Zidane certainly left a legacy as a player, scoring twice as France beat Brazil in the 1998 World Cup final, and volleying an iconic wonder-goal against Bayer Leverkusen that delivered the 2002 Champions League to Madrid.
Houllier suggested that as Zidane had inherited a top squad he would also be judged "on the players he chooses to field and how he develops them".
"He must move the team forward and leave a heritage for his successor, and at big clubs the coaches don't usually last that long," Houllier suggested.
"So he has to move the players forward individually and the team forward collectively. His vision of play, the way he trains the players will be key," said Houllier.
Asked if Zidane would be able to help Cristiano Ronaldo improve his game Houllier said the fact he's been a great player himself could count.
"He could add to the game of these great players with the smallest of details, because at that level it's the details that count."
Another challenge for Zidane would be getting to grips with the "Armada of talent" he was inheriting.
"He'll need to understand the different types of egos, the perfectionists, the flighty ones, and the winners," Houllier said.
"He'll know about that having been the assistant to Carlo Ancelotti," the Frenchman said in reference to Zidane's apprenticeship under the Italian coach at Madrid in 2014-2015.
Houllier, remembered in France as the national coach who failed to qualify for the 'USA 94' World Cup, ended however on a word of warning for his countryman.
"Finishing second at Real Madrid is seen a failure, never mind finishing in fifth or sixth place."
Zidane's debut as Real coach after 18 months in charge of Madrid's feeder team Castilla comes on Saturday against Deportivo La Coruna.