Jay Rodriguez’s second-half header condemned United to their first loss at home in the league since December and meant Manchester City were crowned Premier League champions with five games remaining.
Manager Jose Mourinho accused his players of letting victory in the Manchester derby last week go to their heads following the defeat to the league’s bottom side.
And Neville conceded that he was surprised by the result but insisted Mourinho needs to get rid of the players causing ‘attitude and consistency problems’.
Neville said on Sky Sports’ Monday Night Football: ‘No I didn’t see it coming, it was a dismal, weak day for United. They started the season trying to rid themselves of these performances.
‘Mourinho referred to attitude and consistency, he needs to identify the ones causing those problems and they need to go. I think there will be three or four players leaving and the same number coming in.
‘He’s got to make that gap up and it’s going to be tough. Consistency is about mentality and the players fell well below that considering the last couple of weeks.’
The result at Old Trafford confirmed Pep Guardiola clinched the league in his second campaign at the Etihad and in the process ended a remarkable run of second-season success for his United counterpart Mourinho.
The Portuguese has previously won the league in his second season at Porto, Chelsea (twice), Inter Milan and Real Madrid.