You BetCity are in the driving seat for Manchester clash
Mancini's men look to be the side to back again after beating United twice in league last season
No match in early December can be a title decider, but the outcome of tomorrow's Manchester derby is likely to be hugely significant nonetheless.
City will go top with a win, but victory for United would put them six points clear of the reigning champions and give them a huge boost going into the Christmas programme.
City won both derbies in the Premier League last season and those victories made all the difference in the end.
The six-point swing in City's favour enabled them to finish level on points with United, having recovered a seemingly lost cause to go back to the top with a 1-0 home win over their neighbours in the third-last match of the season.
In the first meeting, at Old Trafford in October, City had won 6-1 to give them most of the eight-goal advantage that proved decisive in the end.
It is a further indication of how close the title race was that, if the result at Old Trafford had been a 2-1 win for City, the two Manchester teams would have finished level on points, goal difference and goals scored.