Houllier said: "Macca was very influential because of his attitude, experience and his talent. It is not a co-incidence that Chelsea are doing well with a wonderful player like Zola because his experience is helping them a lot. But this is not a player you can find easily.
"When you can't find that type of player you have to try and develop your own players and give them time to become leaders. I can see one or two of the players at Liverpool now becoming that type of player."