The Giallorossi are trailing badly in the Serie A standings, a full 10 points behind their arch rivals ahead of the Sunday afternoon showdown.
"There isn't any difference in quality between the two sides, it is merely down to this moment in the standings. They are two teams battling for the top spots and we'll see who is up there come the end of the season."
The Biancocelesti are the surprise leaders and are unbeaten since the opening weekend, but Ranieri believes it is only a phase - and they know it.
"Lazio know that sooner or later they will lose. Their biggest fear is that it will be against us. They will be extremely tense.
"This cannot ever be a match like the others, as the derby is the derby. There are no favourites. I hope it will be a spectacle of pure sport and let the best side win. We'll both give it our all, but within the rules of the game."