The former right-back has staunchly defended the Portuguese manager this season, but it looks like he may be running out of patience.
Mourinho is renowned as an experienced boss who has been able to achieve consistent success throughout his career, but Neville says this is what his beloved 'Red Devils' are now missing.
Sitting 10th in the Premier League their manager remains under pressure and although he is far from calling for his sacking, Neville's words will not do much to help.
Speaking at the launch of former team mate Ben Thornley's book he commented on their patchy form:
''Jose Mourinho must be pulling his hair out. He is a manager whose career is prided on consistency. He has been that for 14 years. Now he hasn’t got a team that is consistent. Every weekend is different, Brighton, Watford away, West Ham, the second half at Chelsea.
''Even within games, their form is different from one half to the next. The first half against Tottenham, incredible. Best 45 minutes of football I’ve seen at Old Trafford for five years. The next 45 minutes, desperate. Then you are back down again.''