Pep Guardiola once said that the diagram is simply a series of numbers. However, few coaches have associated their name with a fixed tactical system like Ruben Amorim.
In the Manchester Derby, Man United entered the match with the intention of taking advantage of long balls early to the sidelines, but all options fell into a deadlock. inaccurate crosses and disjointed combinations have completely left Amorim's side at a disadvantage. Phil Foden opened the scoring in the first half and Erling Haaland's double in the second half sank the visitors.
This Derby was not simply a big defeat, it continued to expose all the weaknesses in Amorim's system. Man United was often cut off, the two-man midfield was constantly exploited by The Citizens, while Bruno Fernandes was once again pulled back too deep and lost his inherent influence.
Whether calling this formation 3-4-3, 3-4-2-1 or 5-4-1, Man United always have to play with two central midfielders. This is the capital. When the opponent stretched the field with the attack trio, the "Red Devils" midfielder pair was forced to cover an area that was too large, easily creating a "3 vs 2" situation.
After the Manchester Derby, Gary Neville shared: If Amorim wants to operate this formation in the best way, Man United's midfield cannot be cared for. Amorim needs Roy Keane and Steven Gerrard in the squad to control the midfield.

As soon as Amorim arrives at Old Trafford, the biggest question is how he will use Fernandes? Previously, the Portuguese midfielder was always free to play as a classic "number 10", launching decisive passes or finishing from a distance.
However, in the 3-4-2-1 system, the role of "number 10" does not exist. Amorim forced Bruno to drop deep, becoming a useful midfielder from the home field. As a result, the M.U captain's touch map focuses on the home half, something not seen in the last 3 Premier League seasons.
The problem is that Bruno Fernandes is not the type of midfielder to intercept or defend. When he had to shoulder the responsibility of defending, he showed limitations, but when he moved high, he left the midfield empty. Therefore, the "Red Devils" have both lost their creativity in the upper ranks and have not had enough steel in the midfield.
Another weakness is the wing-backs, a key position in Amorim's formation, they have barely created value. Last season, the four of Dalot, Shaw, Dorgu and Mazraoui contributed just four goals and provided four assists. This is too small a number compared to the requirements of a system that needs wing-backs to contribute 15-20 goals per season like Chelsea under Conte.
At the Etihad, Amorim uses Dorgu and Mazraoui. Both played well in defense but were completely deadlocked when participating in attack. They have no dangerous cross shots, no forced breaks from the wing, Man United are easily stifled by Man City.
Man United are still relying on the old framework in defense. Leny Yoro brings hope but other central defenders such as De Ligt, Maguire and Shaw lack the speed and flexibility to play high-altitude pressing. This makes it difficult for the "Red Devils" to deploy a style of play similar to Liverpool or Arsenal.
In addition, the goalkeeper position continues to be a concern. Andre Onana has left, Altay Bayindir has played erratically, sometimes starting well, sometimes making elementary mistakes. In the Derby, he was almost robbed by Haaland in the 5m50 area. It is not ruled out that new signing Senne Lammens will soon be given a chance right in the match against Chelsea at the weekend.

Can one argue with Amorim about being steadfast in his philosophy or is he too stubborn with an inappropriate system? When faced with teams that know how to retreat, Man United immediately fell into a deadlock. When pressing high, they are more likely to get patted in the face and lose balance. The 3-4-2-1 formation gradually revealed itself like a "short shirt". If he does not change flexibly, Amorim will find it difficult to escape the spiral of failure.
The Derby against Man City could be seen as Ruben Amorim's toughest warning since he took the hot seat at Old Trafford. The 3-4-2-1 formation he believes is absolutely causing Man United to lack creativity, imbalance, and be vulnerable to opponents exploiting deadly gaps.
"Red Devils" fans had expected Amorim to bring a clear philosophy, but at this point, what they witnessed was only disruption and disappointment. If he does not adjust quickly, the tragedy at the Etihad will recur and Amorim's future at Old Trafford will no longer exist.