A 0-0 stalemate at Queens Park Rangers on Tuesday has left City playing catch-up once again and added extra spice to Sunday's encounter at the Etihad Stadium.
A defeat and City could find themselves 10 points adrift, deep into the second half of the season when United, who visit Fulham on Saturday, are traditionally strong.
Having won their previous four in the League, Tuesday's goalless draw was as unpredictable as the behaviour of mercurial striker Mario Balotelli, whose time with City appears to be nearing an end.
The Italian's departure would leave the club a striker short, but perhaps with one less problem to deal with as the title race starts to pick up the pace.
His undoubted talent sporadically lit up the Premier League, but his firework personality meant the indiscretions in the end outnumbered his occasional spectacular contributions.
City lacked the killer instinct to break down QPR and on Sunday will face a Liverpool team who have also frequently come up short when looking to deliver a knockout blow.
Capable of weaving pretty passing patterns, the Merseysiders have all too often lacked the mettle for a scrap or had the resolve to dig deep and grind out a result when the chips are down.
Having stumbled out of the FA Cup against third tier Oldham, they showed what they are capable of on their day with an impressive first-half display against Arsenal on Wednesday, but again stumbled under pressure and ended up drawing 2-2.
New signing Daniel Sturridge has shown he can work well in tandem with 17-goal striking partner Luis Suarez while the club's second January acquisition Brazilian playmaker Philippe Coutinho could make an early debut on Sunday.
Arsenal, who showed their own defensive fragility in a comical and error-strewn first half against Liverpool, will face a different challenge at home to the physical and direct Stoke City.
United play Fulham a week after they strolled to a 4-1 victory over the west London club in the FA Cup fourth round.
That match was billed as the return of Dimitar Berbatov to his former club, but the Bulgarian's contribution amounted to little more than a lackadaisical stroll around his former Old Trafford stomping ground.
United maintained their own title march with a 2-1 win over Southampton on Wednesday thanks to two goals from England striker Wayne Rooney.
Chelsea face a tricky visit to Newcastle on Saturday after their form under interim manager Rafa Benitez again came under the spotlight when they gave away a two-goal lead for the second time in two weeks to draw 2-2 at Reading in midweek.
Tottenham Hotspur's form has also faltered and they will be hoping to win their first match in four against West Bromwich Albion on Sunday after three successive league draws.
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