Perhaps the players are simply not good enough. The pressure of Manchester United can either elevate you or drown you. Most of the players who join United are given ample opportunity, given huge salaries and pampered with excuses. No other reputable big club does this - if Zhirkzee was at Real Madrid, he would be binned off for not stacking up. Manchester United, however, keeps rewarding failure and I am not sure why. Ten hag, Rashford, Sancho, Maguire etc all still rolling up at the club when they should be ruthlessly binned.
The fact is, some players and managers can't cut it under the lights of Old Trafford. Excuses won't change that.