But Houllier has discounted their arguments, and dismissed the 2-0 defeat at the Mestalla as a 'bad day at the office'.
He said: "We will show the Spanish that we are not a Mickey Mouse team. Some of their players seem to have suggested that is the case - but we'll see.
"Some of their players have been disparaging about our league, but I think that is wrong. I don't see how you can compare leagues and say we wouldn't finish in the top four in Spain. In England, it is very different in terms of pace and intensity.
"They can say what they like but it is very difficult in England, very tough, and there is no way you can compare it with Spain.
"We had a bad day at the office in Valencia and that is why they are being critical now. But our weaknesses on that day have now become our strengths, and maybe what happened gives us a little more motivation."