Pressure is growing on Manuel Pellegrini for top-four finish
Manuel Pellegrini has six games to keep Manchester City in the top four or he will be sacked.
While there is no great desire at the Etihad Stadium to remove the man who took them to the Premier League title 11 months ago, failure to qualify for the Champions League would have only one possible outcome.
Liverpool, in fifth place, last night moved within four points of City, whose drubbing in the Manchester derby was their fourth defeat in five matches.
At first glance, Pellegrini would appear to be fortunate should he survive in his job should he finish fourth or fifth.
His defence of the Premier League title has proved worse than the one that cost his predecessor, Roberto Mancini, his job.
Mancini finished second and reached the FA Cup final, however, there has been none of the internal dissent under Pellegrini that cost the Italian his job and crucially, City's determination to pursue Pep Guardiola means there are few potential replacements.
Guardiola's contract as Bayern Munich coach expires in June next year and it would be hard to find a credible alternative to babysit the squad until the world's most sought-after manager makes his intentions clear.
If Pellegrini is removed, Patrick Vieira, City's director of elite development - who has ambitions to go into management - would be a serious candidate.
Whatever the fate of their manager, there is a realisation in the dressing room that the slide that Pellegrini described as "throwing our season in the garbage" has to be halted.
Joe Hart described the 4-2 defeat at Old Trafford as "one of my worst days in a Manchester City shirt."
The England goalkeeper added: "We let ourselves down and we let our supporters down. There are six games to go and they are so big for us. It is essential to try to finish third. We have got to get our heads down and win these massive games."
Whoever is in charge in the summer will have to oversee a major overhaul of what is now the Premier League's oldest squad, with most of their key members brought to the Etihad under Mancini or his predecessor Mark Hughes.
City were taken apart at Old Trafford by a United side that under Louis van Gaal prepared meticulously.
"We said earlier in the season that we were working on things and it was going to take time," said United's captain, Wayne Rooney.
"The training we have been putting in is starting to show. We have been training for each game in a different way, depending on how the opposition plays. There is no detail ignored.
"We have got players who can score goals from midfield and we felt that was going to win us the game - so it proved.
"We knew some City players are not the best at tracking runners and defending. We felt we could make them pay for that and we did."
"There is more space in the bigger games and those kinds of teams like to attack. We felt against City we could capitalise on it."