#3 The improvement made by rivals
As if being knocked off their perch as the top club in England was not enough, Manchester United fans have had to also look on as clubs who they hitherto looked down upon have overtaken them in the English football hierarchy.
Manchester is no longer the premier club in England, they are no longer the premier club in Manchester - that honor belongs to Manchester City these days, as their once mocked neighbors have become the model team in the club which all other teams look up to.
United fans only have to look over at their neighbors and the brilliant football being played and compare with the drab football on display at Old Trafford, or looking further down the M16 at what Liverpool is doing.
Managers like Mauricio Pochetino, Unai Emery, Maurizio Sarri, Jurgen Klopp and most gallingly Pep Guardiola are not only winning matches, but also winning them well and convincingly by playing an exciting brand of football which goes in stark contrast with what Mourinho offered at United and on the basis of this, it was inevitable that he would struggle in the face of competition from these progressive managers.