Houllier knows all about Heskey's qualities after splashing out £11 million to buy him from Leicester when in charge at Liverpool a decade ago. And he responded by netting once and setting up two goals for Ashley Young when he came on as substitute in the 3-1 Carling Cup win over Blackburn at Villa Park.
Houllier said: "With Emile it is a matter of confidence - like all strikers, but probably more with him. I know what he can do but he showed a few things in training that indicated to me he was in a good form period."
He added: "He knows I like him. The attitude of the subs is very important and they came on and brought something.
"They brought their freshness, a desire, and they were very quickly at the same level as the other members of the team. Emile came with that attitude and did well."
Heskey has not always been a fans' favourite in his two years at Villa but Houllier believes he may thrive on winning over supporters.
He said: "At the end of the day, maybe it is another challenge for him, to win the hearts of the fans again.
"The fans were good to him when he scored and don't forget he was involved in the second goal. He chested the ball for young Nathan Delfouneso and the third goal came from his cross. He was extremely decisive."
Blackburn looked in control after leading but were unable to cope after Houllier changed tactics at half-time and pushed Young into a free role behind John Carew and then Heskey.
Rovers manager Sam Allardyce said: "The game lasts 90 minutes - not 45. That seems to be quite a problem for us at the moment, the second half. We've got in front in most games we play in and can't seem to maintain our lead."
Source: PA
Source: PA