The Reds have won just five of their eleven home games this season as they struggle to reach what was dubbed the 'minimum target' of fourth place by chairman David Moores.
Houllier said: "We have lost too many points at home. But there have been a number of games where we have been unlucky or where we've not been able to field our key players.
"The next two home games against Manchester City and Portsmouth are very important to our season. We are aware of that."