"They seem to be able to dig deep within themselves and perform when they have to and because our vision is to win the trophy, we need a good performance in Leverkusen."
The last time that Houllier attended an away match was back in September at Newcastle when Liverpool won 2-0. He said: "The surgeon gave me the green light to go to Germany.
"In an ideal world he probably wishes I had waited a bit longer.
"At the same time he felt I was becoming a bit itchy and wanted to go. As I am under control, he is happy for me to be back in business.
"As I said to the boys, I want to share these moments with you. These nights in Europe are always special.
"It is my first away game since Newcastle and I would be happy to get the same result we had that day."
Houllier's presence is bound to give Liverpool a lift going into the second leg.
With a potential semi-final against Manchester United to come it is a massive game for the four-times European Cup winners.
Leverkusen strengthened their grip at the top of the Bundesliga with a 2-0 victory over Cologne on Saturday.
Houllier said: "The fact that Leverkusen are in front of Bayern Munich in the league tells you everything about them. They seem to be on a high.
"Don't forget, though, we could have beaten them by more than one goal last week.
"We also kept a clean sheet and that was very impressive. What we are also showing at this stage of the season is great consistency. That's why we are here."
Leverkusen manager Klaus Toppmoller is aware one Liverpool goal in Germany would leave his side needing to score three times but he is hoping to claim "a miracle triumph" against Houllier's men.
Toppmoller said: "We are pushing ourselves from game to game and hope to mobilise all our energy again tonight, and to make the miracle happen.
"We'll go into the match with a lot of energy and in an attacking frame of mind, but there's no doubt that Liverpool are the big favourites.
"Liverpool are a compact side and a good defensive team - 1-0 is a good result in European competition. But we will be fit and raring to go. We can win this."
Houllier could reshuffle the side tonight with Portuguese defender Abel Xavier ready to return to the left-back role after suffering a hamstring strain.
With Xavier in defence, Norwegian John Arne Riise could go into midfield with Czech Republic international Vladimir Smicer dropping down to the bench.
Bayer Leverkusen (0) v Liverpool (1). 7.45pm, tonight, Ulrich-Haberland Stadion (Live on ITV Sport).
