Although 11 players perform on the field in every game, it remains to be seen which players play the most important role in the team's victory. Some of Manchester United's most important players and those who make an impact in the game are Marcus Rashford, Bruno Fernandes, Casimiro, and Antony. These players play the most important role for the team. The success or failure of Manchester United depends a lot on the performance of these players. Manchester United's defense is not very good at the moment. To perform well in the big leagues, you must have quality defenders, which Manchester United currently lack.
Antony seems will withdrew from Manchester United squad upcoming match after Brazil national teams removed him from main squad due criminal cases happening, its complicated problem for Manchester United next match after international break out against Brighton Albion. Jadon Sancho have early withdrew from Manchester United squad last match against Arsenal and I don't see any good indication between Erik ten Hag and Sancho have good communicating back to main squad.
I doubt with several crucial problem facing by Manchester United make them back to the top standings position and they will play in opening Champion League match in few days later after facing Brighton Albion.