But a 15 point gap looks likley to become an 18 point gap if team selections are an indicator.
Given their fine league form throughout the campaign, no goal conceded in the league since January being an example of that form, it's hard to see City winning.
Joe Ross betting expert at www.footyinsider.co.uk says:
'Sir Alex (Ferguson) has the luxury of no pressure and has played an attacking line-up with Van Persie, Rooney, Young and Giggs in the line-up.
'City have only one real striker in Tevez with a five man midfield. It's damage limitation for Roberto Mancini who has bemoaned the bad luck he has suffered and the fact that he couldn't sign the right players in summer. In truth United have just been superior and loo a great bet to win.'
City would love to inject a little drama into the situation over the final few months and at least some pressure on their rivals down the stretch. Anything less than three points on Monday would eliminate those hopes.
Looking back, the complexion of the title chase changed after the first meeting between the clubs. Pablo Zabaleta scored a late equalizer that seemed like it would salvage a point for City after falling behind 2-0, but Robin van Persie struck late to steal the match back for the Red Devils.
United's victory stretched their edge to six points, and they haven't looked back. The confidence gained by going into Etihad Stadium and emerging with three points really seemed to help fuel their ability to run away from the pack.
If there was any doubt who is top dog before the game there won't be afterwards and even if City go on to win the FA Cup Mancini's future may come under scrutiny by City's owners who expected more.