From Paul Pogba's performance to Jose Mourinho's team selection, we pick out the talking points as West Ham increased the pressure on the Manchester United boss with a 3-1 victory at the London Stadium on Saturday.
More misery for Mourinho
Defeat to West Ham left Manchester United with just 10 points after seven games, equalling their lowest ever tally at this point of a Premier League season.
Mourinho's side have won only three of those games, drawing one and losing the other three to Brighton and Tottenham before the Hammers reverse.
Alarmingly, Marcus Rashford's backheel at the London Stadium was just their 10th goal of the campaign, the exact same number David Moyes had managed seven games into his spell at Old Trafford - and everyone knows how that ended.
Despite receiving backing from above, Mourinho is going to have to start getting a tune from his players fast to avoid the same fate. It's early days but United are already eight points off the pace and out of the Carabao Cup - salvaging something from this season is already looking a tough ask.
The Pogba problem
Despite the building tension between Mourinho and Pogba, the Manchester United manager was true to his word and started the Frenchman against West Ham. Would there be a reaction from the midfielder after all that had gone on during the week?
Pogba, who had the United vice-captaincy taken off him during the week by Mourinho, started on the left of a three-man midfield, which also featured Marouane Fellaini and Nemanja Matic. However, it proved to be a frustrating afternoon for the 25-year-old.
With no options in front of him there were clear public displays of frustration from Pogba as he was forced to turn back with the ball during a frustrating first half at the London Stadium for Manchester United.
There were more clear signs of that frustration early in the second half. Pogba carried the ball from near his own corner flag to near the halfway line but, with a lack of support, he struggled to keep hold of possession before being fouled by Pedro Obiang. He looked far from impressed with his team-mates, throwing his arms up in the air.
Pogba's afternoon was over in the 70th minute when he was hooked by Mourinho. There was a somewhat awkward exchange between the pair as Pogba took his seat on the bench, but the United manager did pat the midfielder on the back. But that's not likely to have changed Pogba's mood as this situation gets set to rumble on.
Where are Jose's options?
When asked why he had left both Alexis Sanchez and Jesse Lingard out of his matchday squad, Mourinho replied: "Options, just options." But on his side's showing at the London Stadium, options are in short supply for Mourinho at the moment.
Anthony Martial failed to make an impact coming into the side in place of Sanchez, while the likes of Juan Mata and Marcus Rashford sat on the bench as a midfield three of Pogba, Matic and Fellaini failed to spark, leaving Romelu Lukaku to cut an isolated figure up front.
Then there was the inclusion of Scott McTominay ahead of Eric Bailly as part of a three-man defence, which left many United fans scratching their heads. The midfielder had only played 30 minutes of football for United before today but Mourinho thrust him into the action, the 21-year-old playing the full 90 minutes in their 3-1 defeat.
"A part of a special character, a special personality, that a team in a negative moment needs this kind of mentality like Scott McTominay has." Mourinho was left impressed with McTominay's display but the move to play him at the back can not be classed as successful as United racked up a third league defeat of the season.
De Gea in decline?
Manchester United's ability to keep hold of David de Gea has been heralded as one of the club's best pieces of transfer business in recent years. But the form of the often impenetrable last line of the United defence has taken an alarming dip this season.
That continued at the London Stadium. De Gea kept six clean sheets in his first seven games last season, this term he's managed just one from his opening seven games. The Spaniard was not at fault for any of West Ham's goals - not even he could prevent Yarmolenko's deflected effort from finding the top corner - but his inability to bail United out at key stages of games this season is clearly having a profound effect.
Mourinho's weekly attempt to cobble together a defence is not helping matters, but for three of West Ham's four attempts to beat a goalkeeper of De Gea's quality, a level of responsibility lies with the United stopper.