The Reds currently lie a lowly seventh in the league table, not even good enough for a UEFA Cup spot, and Houllier is fully aware that his side require the full support of the fans if they are to reach the top 4.
He said: "We need to mobilise our supporters again and have the same response as we did in the cup-tie last week.
"The fans were behind us from the first whistle until the last. They were outstanding. This game is just as important, especially when you look at the results last night which didn't go our way.
"Arsenal will have a close battle with Manchester United for the title, I believe we are short of that battle now but not short of being a Champions League contender.
"We are certainly outside the title race at the moment, but we are not outside the Champions League.
"The Champions League is as good as it gets for us, but you never know, we will do our best in every game."