Houllier said: "Sami has been outstanding in every match since I gave the captaincy to Steven Gerrard. He's just kept his head down, worked hard and responded in the way I knew he would. He is playing like the player we know he is.
"He has always been a leader and is still one of the three leaders I have in the team. I'm glad to have all three of them available again tomorrow. Sami, Stevie and Michael Owen will all be playing. We will need them and the fans because it's going to be hard game.
"I like these European nights at Anfield and I'm pleased it looks as though we are going to have another sell-out crowd. The fans make a difference on these occasions. They give us some-thing extra."