As I'ts been said, I think that there are shitter teams around and below them, so they won't go down.
The bigger problem for them though, is if they get any long term injuries(ie: out for 6weeks - to the end of the season) to key players like Cahill, Baines, Neville. etc. Because their squad is paper thin, and losing some of their mainstay first-teamers will impact on them greatly.
If that happens, I can see it being 1997 all over again........
......message to self. Buy some 3 in 1 oil, for the squeeky trap door hinges.