#4 The Ex-players' factor
The comeback against Newcastle could prove to be the turning point for United this season. Alexis Sanchez is still a player who could be a threat on his day. Whatever the case, this game is delicately poised and promises to be an interesting game.
As seen in some games over the years, players are usually extra-motivated when facing their old clubs. United could have all three Chelsea former players start Saturday's game, with the likes of Matic, Lukaku and Mata in their ranks. They could be extra psyched up to get a positive result out of the game which could decide the outcome.
All in all, it looks more likely a Chelsea win, owing to the fact that United haven't won on this ground since 2012. However, United cannot be written off, they still have players who can make the difference on their day.