I am not overly confident going into this game given our record against fellow top 4 sides this season. I agree with Alpha, we should not fear Chelsea, they do have some very handy players, but no outstanding ones like City or United or even dare I say Liverpool.
I think if we can control the midfield we should win, if we play well we should win.
It really is a must win game IMHO, anything less will be a poor result and will put us right amongst it assuming City and Liverpool both win next weekend.
Edited to add: If we harbour any ambitions to strongly challenge this season then we MUST win our home games against our rivals as it looks like we won't be getting anything at their grounds.