Despite Alexis Sanchez netting the second goal in the 2-0 victory over Huddersfield, the Portuguese manager wasted no time in telling his fans that they are not doing enough to support the team.
When talking about Sanchez, Mourinho said: "He played only three (matches since joining from Arsenal) and the first at Old Trafford, and I think Old Trafford, in spite of being a quiet stadium, the pitch is big, the grass is nice and obviously the players feel very comfortable playing here."
Asked to clarify his comment the former Porto man said: "It's not Portsmouth. I remember Portsmouth - such a small stadium, the atmosphere was absolutely incredible. In here, the atmosphere is a bit quiet and there is not very (much enthusiasm). But the players like to play at home."
It is not the first time Mourinho has turned on his own fans this season, with him previously making comments after wins against Tottenham and Leicester earlier in the year.
Romelu Lukaku scored the first goal for the 'Red Devils' before Sanchez tucked in the rebound after seeing his penalty saved in a match where Mourinho also dropped Paul Pogba to the bench.