United have already been beaten three times in the Premier League this season and Mourinho is under increasing pressure to turn results around quickly at Old Trafford.
Former United players have heavily criticised Mourinho and his decisions, but Neville believes there is an issue at the top of the club hierarchy.
Neville does not think United back Mourinho as they did with Sir Alex Ferguson, and imagines any manager would struggle in the current environment at the club.
I do think the problems come from above. I dont think its settled, Neville said on Sky Sports.
I dont think the quality of football knowledge is there above Mourinho. So I think any manager would coming in would have difficulties.
If you look at the three years and people saying Mourinhos [time] is over with Jurgen Klopp and Pep Guardiola [taking over]. I dont buy into that.
We used to look at the Jose Mourinho masterclasses, we were the one who celebrated these type of victories. There is still a way to win football matches with this type of football.
He added: There are undermining him above him. Sir Alex was given control and if he wanated a player theyd back him. Im not sure Jose has been given that level of control.
Several off-the-pitch incidents have caused controversy at United, with Mourinho repeatedly lashing out at the media and conducting an row with Paul Pogba in full view of TV cameras.
And Neville warned Mourinho he needs to adjust his behaviour at a club like United.
I do think this is a blip on his career, but its just the confrontation thats a problem openly on the training pitch and with the media, Neville said.
I think he needs to settle down. Manchester United is not that type of club.
There is still that Bobby Charlton influence in the board room where you cant do that. He just needs to settle down.