Houllier said: "We are not disappointed with his performances, we just need to adjust it to the English game. He could, with a bit more sharpness, but he will develop that.
"El-Hadji has come back from the World Cup and even Brazilian Ronaldinho is struggling at Paris St Germain - and he is probably one of the best players I've seen.
"When players come back from the World Cup you usually seem to get them after Christmas. I don't know why. It is not just physical, it is mental. It takes a lot from you a tournament like that.
"You need to take time and be patient. One of the qualities about this club is that they give you patience and time. You don't change your judgement because of one or two bad games.
"When Patrick Vieira was at AC Milan they didn't give him time and now you can see the player he has developed into.
"El-Hadji is a special player because he is unpredictable. He can create and he can beat people. Don't forget, he is used to having a break at Christmas.
"He can be a better goalscorer, it is a matter of believing in himself and I would back him to do that. At the moment, I want him to strengthen his game because in England you don't have time. There is always pressure from different quarters. But El-Hadji has been involved in either the goal or final assist in 25 per cent of our goals this season."