AT Ewood Park on Monday night, Manchester United's travelling fans had a new song to sing. As Antonio Valencia and Ashley Young sent their team five points clear at the top of the Premier League, to the tune of Football's Coming Home they roared out: "City's cracking up, they're cracking up."
The news from the other side of Manchester does not do much to contradict such an assertion. Sergio Aguero, City's most potent forward, is being publicly courted for a return to Spain. David Silva, the fountainhead of their point-gathering potential, appears hollow-eyed with exhaustion. While their enfant terrible, Mario Balotelli, has yet to appreciate that fighting for the title does not mean scrapping with team-mates.
His latest escapade - with the gold-digger once associated with Wayne Rooney - has been described by his agent as "a brief encounter". Which makes him sound like the Boris Becker of football.
But what has really given an impression of an institution wilting under pressure has been the demeanour of the manager. Early in the season, Roberto Mancini looked ideally equipped for the challenge: unflustered, superior, endlessly cool in his natty scarf.
During the game against Sunderland, however, he appeared anything but the master of his emotions. He was all too visibly frustrated, distant, unhappy.
Then, in his post-match press conference, he said that if United were to win this Sunday after picking up three points at Blackburn, the title was theirs. Which, given that there are still seven games to play, including a home derby, seemed the most premature surrender. Coming on top of revelations that he did not trust some of his players, or the club medical staff, it did not present the image of unity required as the season enters its business end.
This is the point of the playing cycle where the manager becomes the most critical employee at a title-chasing club. At Old Trafford, much is made of the continuity of success in the dressing room, of the long-serving players passing on winning habits to new recruits. But the manager's conduct is easily as important.
Alex Ferguson has undoubtedly had to learn how to be a title-winning boss.
The most significant thing Ferguson has understood in his years of title-winning, however, is how to husband his resources.
When City were bulldozing all before them in their autumnal pomp, it was Silva and Yaya Toure who provided the spark. They looked unstoppable. Mancini was clearly aware of their importance and played them in every game. With the result both now look spent. And no wonder.
Silva has made 12 more Premier League starts than Valencia, who, on Monday, as Paul Scholes passed the ball to him time after time, provided almost all of United's attacking threat and verve.
This has been the real genius of Ferguson over the years: if football awards were given to the players who have most influence on the final stages of a title race, one of his would win every season.
Instead, with the voting necessarily closed well before trophies have been accounted for, those who sparkle in midwinter pick up the gongs. Who would have thought, in January, that Valencia might be the most critical player in the championship run-in and not Silva? Probably only Ferguson.
Mancini has won titles before, in Italy. He knows the course, he knows how to run a marathon. The difference this time is largely in the nature of his adversary.
He cannot have been up against one as astute, one who makes as few errors, as his rival across town.
And whatever happens in a title race which still has the potential to go to the wire, he will now know how it should be done. Mancini has an inquiring mind and, looking back in the future, will be a better manager for it.
Such a prospect does have one significant caveat. After watching him apparently falter there on the touchline, a question is starting to form: will his employers gift him sufficient time to learn the lesson?