Manchester United's comprehensive defeat in the Etihad derby brought Jose Mourinho's side down to earth with quite a bump after victories over Juventus, Bournemouth and Everton had lifted the mood around Old Trafford.
It means United have lost four of their opening 12 top-flight games for the first time in 28 years and have a negative goal difference at this stage of the season for the first time since 1977.
Most of the flak has been aimed at Mourinho for his tactics and the way he uses the players at his disposal, but United's highly-paid squad are also responsible for the poor start.
Sportsmail takes a look at the biggest disappointments so far this season.
ALEXIS SANCHEZ
Mourinho said we wouldn't see the best of Sanchez until this season after he signed midway through the last campaign in January, but that simply hasn't happened.
Watching the Chilean climb off the bench to give another largely ineffective performance at the Etihad on Sunday, it was hard to believe that City battled so hard to get the 29-year-old before giving up the fight when United agreed to pay him £500,000-a-week.
Sanchez hasn't lost the talent that made him such a great player for Arsenal – there were glimpses of it against Juventus in Turin last week – but he hasn't produced it nearly enough to justify the effort made to bring him to Old Trafford.
FRED
Another player at the centre of a tug-of-war between the two Manchester clubs who has disappointed since choosing United.
The Brazilian cost £52million when he moved from Shakhtar Donetsk in the summer but has done little to vindicate that transfer fee even in today's inflated market.
The 25-year-old has made just nine appearances and seven starts in all competitions, struggling to hold down the third midfield birth alongside Paul Pogba and Nemanja Matic.
When Mourinho needed a replacement for the injured Pogba against City, he opted for a half-fit Marouane Fellaini and left Fred as an unused substitute on the bench.
ROMELU LUKAKU
The big Belgian scored 27 goals in all competitions last season following a £75million move from Everton, but his output has dropped off significantly this term.
Lukaku has failed to find the net in 10 appearances since opening the campaign with four goals in his first five games.
He came off the bench to win United a penalty in the derby as Anthony Martial scored from the spot with United's solitary shot on target, but the former Everton man appears to have lost his confidence and touch in front of goal.
Some would argue that the powerful, bustling Lukaku will never be the world-class striker United need to compete at the highest levels of the game.
NEMANJA MATIC
The Serbian brought an element of stability to United's midfield alongside the more erratic Pogba last season after he making a £40m move from Chelsea to rejoin his old boss Mourinho.
Matic was an automatic starter and made the line-up for 35 of United's 38 Premier League games.
However, his form has dipped this term and it was no surprise to see reports that some of his teammates are surprised by the loyalty shown by Mourinho this season in refusing to drop the 30-year-old midfielder.
His failure to pick up Ilkay Gundogan before the German scored City's third goal at the Etihad was typical of Matic's loss of form.
MARCUS RASHFORD
Mourinho understands the significance of keeping a homegrown player in the squad at United, and in that sense Rashford has become something of a dilemma for the manager: a young striker who doesn't always deserve the game time he is given.
There is no doubting Rashford's ability but he seems to have gone backwards under Mourinho. He looks unhappy in a wide role and struggles to make an impact when played through the middle, as he was at the Etihad.
While Rashford comes alive for England – with three goals in four games for his country this season – his performances for United have been less effective.
The late winner at Bournemouth earlier this month was a rare highlight in an otherwise disappointing season so far.
ERIC BAILLY
The disappearance of Eric Bailly will go down as one of the more intriguing mysteries of Mourinho's reign at Old Trafford.
For so long the warrior figure that Mourinho wants in his defence – think John Terry, Marco Materazzi and Pepe – Bailly has slipped down the pecking order and practically out of sight at Old Trafford.
It's understood the Ivory Coast defender upset his manager by withdrawing from the home defeat to West Brom in April due to illness and then reporting fit for training.
He briefly regained his place this season but was substituted after just 19 minutes against Newcastle last month with United two goals behind.
Former Old Trafford favourite Rio Ferdinand predicted that it was the end of Bailly's career at United, and he may well be right.
L10NELMESSI
229
Sanchez is the biggest failure then anyone considering the amount of money he is getting.. After his every match Man united fans feels like..
Wiuacekoyz
150
mourinho is the cause, and all those mentioned players are only symptoms. so you don't treat the symptoms but the cause. enough of mourinho 's excuses. there are so many managers out there looking for jobs. I even wonder if ed woodward is related to mourinho, because he is very blind and comfortable while the club is going down.
mkorea
142
I think the problem here is jose Sanchez was our starman(speaking as an Arsenal fan) but he's failed to live up the expectations of Old Trafford faithfuls Lukaku was the best striker of Everton,mourinho signed him with huge fees only to see him fail to deliver what he was brought to do Rashford was brilliant under LVG.He was regarded as Rooney's replacement among united fans but see what he has come to. the list is on....... what could be possibly be Mou's influence on these players? In my opinion,I think he has this jose's attitude of regarding himself as the best(that he has won many trophies) so every player should respect and glorify him as a person. This in turn put ruin player-player relationship and players-coach relationship. For man united to prosper,they need to get rid of jose
nipamnopuz
115
Flops due to: 1. Ed Woodward.. he is useless and incompetent compared to David Gill 2. Mou himself too useless with his outdated takticks, the world of football has advanced and he's still stack to 2010 tack that managed him to win trepple. Man U.. hope you will sack Mou and Ed once you find yourself in a relegation zone. Giggs assisted by Callik or Zidan assisted by Callik.
mesaz
112
I assume that the current management were responsible for the player purchases ( except for Rashford) and assuming that they were bought for their talent and expected contribution, why have they failed? I find it hard to believe that they suddenly become talentless, what is it? is it the aura of the club and it's expectations or is it the way they are managed? I suspect it's the latter as it's the managements role to get the best out of the players individualy and collectively and that is just not happening I'm afraid this is not the United that used to excite most of my life....and I am 70.
jimcpry
107
Guys those players Alex is or Lukaku are not failures but mourinho himself..those guys were excellent were they from but why not at man u?he doe's not use them correctly..pogba was superb at juvenile but now he's struggling why?it's because of Mr so called special one..