The 24-year-old moved to Anfield in the summer from French side Lille and has had decent start to his first season playing abroad.
Houllier feels the young Frenchman can show the same class as Zidane but that he must toughen up his game in order to handle the rigours of Premiership football.
Houllier said: "Bruno has got great skill, good vision and an eye for the pass.
"I don't make comparisons with Zidane lightly and I believe he can become an important player for Liverpool.
"Bruno has the same kind of touch and style that Zidane has.
"There's a lot of similarities between the two when they're on the ball.
"The difference is that Zidane is 30-years-old and has a wealth of experience while Bruno is 24 and playing abroad for the first time.
"The Premiership is very hard physically and Bruno needs to become a little bit tougher.
"It's something that players new to England have to get used to.
"It was something Robert Pires had to learn to cope with."
