#3. Failure to involve Romelu Lukaku and Marcus Rashford
A constant criticism of Romelu Lukaku is that he disappears in big games, and the Chelsea game was no different. While performances like these have earned him a reputation of a "Flat-Track Bully", you have to sympathise with the Belgian and United frontman, who was left stranded alongside Marcus Rashford by his team's midfield.
Manchester United's top scorer had no say in the game whatsoever, and fingers have to be pointed at the Man Utd midfield who have failed to transition from defence to attack smoothly in Paul Pogba's absence.
Lukaku has now failed to score in his last six appearances for the club, his biggest drought in a Man Utd shirt, and the absence of his partner in crime, Paul Pogba is at the heart of this disheartening form for one of Premier League's most ruthless goalscorers.
Marcus Rashford was comparatively involved a lot more, but still not anywhere near enough. When Man Utd started attacking with 20-or so minutes to play, Rashford was constantly dropping deep and drifting wide to support United's last-ditch efforts but the Chelsea defence dealt with him well and kept him pinned on the left flank.