How has it come to this? How has a Manchester City side that won back-to-back Premier League titles and a domestic Treble last season fallen 14 points behind Liverpool before Christmas?
City’s derby defeat means they have already lost four times in the league — the same as the whole of last season.
It is Pep Guardiola’s worst start in 11 years and one that can be blamed on a number of problems that have beset the champions.
City's problems at centre-half
Nothing has contributed to City’s issues more than their crisis in central defence.
The folly of not bidding higher to compete with Liverpool and Manchester United for Virgil van Dijk and Harry Maguire as replacements for the departing Vincent Kompany was exposed after Aymeric Laporte was struck down by a long-term knee injury in August.
It has forced Guardiola to switch Fernandinho, one of his most effective players, from defensive midfield to centre-back alongside the injury-prone John Stones and unreliable Nicolas Otamendi.
Fernandinho’s midfield replacement, £62.8million summer signing Rodri, is still adapting to the Premier League and, defensively, City are no stronger for it. They have conceded 19 goals in 16 games — just four less than the whole of last season.
The left-back conundrum
The problems in the middle have deflected from another major issue on the left side of City’s defence. With Benjamin Mendy making only 19 Premier League starts due to injury in the two-and-a-half years since he joined City, Guardiola has tried a number of players at left-back — Oleksandr Zinchenko, who is currently injured, Danilo, Fabian Delph, Laporte and Joao Cancelo —– but it remains a problem position.
On Saturday, he left two full-backs — Mendy and Cancelo — who cost a total of £112m on the bench and opted to play Angelino instead.
The Spaniard was exposed on only his fourth Premier League start as United opened up City down the left.
Falling into Liverpool's shadow
No manager demands more from his players than Guardiola, but there is a feeling City are struggling to maintain the intensity of the past two years in the face of another fierce challenge from Liverpool.
When Guardiola appeared with Jurgen Klopp at a recent awards dinner and remarked that the two managers would happily swap their Premier League and Champions League trophies, he was only half joking.
Europe remains the unconquered summit for City, and they seem to be struggling to match Liverpool’s passion to win the title.
The mood around the Etihad this season has not been helped by a perception that a number of VAR decisions have gone against City, and a grievance over Bernardo Silva’s one-match ban for a racially offensive social media post about Mendy that was meant in jest.
Guardiola's future in Manchester
Speculation over Guardiola’s future has also been unsettling. The City boss will be out of contract at the end of next season, when he will have been at City longer than he was at both Barcelona and Bayern Munich.
There are growing doubts that he will sign a new deal after his wife Cristina and their youngest daughter moved back to Spain in September.
Guardiola has been increasingly irritable of late and it was not unusual to see the City boss emerge early for the second half on Saturday to engage in animated conversation with fourth official Mike Dean.
David Silva's fading powers
David Silva is one of the best players the Premier League has seen and a key figure in City’s success, but the 33-year-old’s powers are on the wane in his last season at the Etihad.
Even so, Guardiola has started Silva in three games in the space of a week at the expense of Phil Foden. As captain, Silva also lacks the leadership qualities of Kompany whose presence has been sorely missed in addition to the long-term injuries to Laporte and Leroy Sane