The signings of Zlatan Ibrahimovic, Paul Pogba and Henrikh Mkhitaryan only helped raise expectations, as did the three wins from their first three league matches.
It's not all gone according to plan for the Red Devils since then, though, with United currently sitting sixth in the table, a full nine points behind leaders Chelsea.
The 4-0 demolition of Feyenoord on Thursday night has gone some way to lifting supporters once again, however, and with struggling West Ham next up at Old Trafford, there's even more room for optimism.
But it will all end in disaster for the Manchester club when May comes around, if the below stat is more significant than just being a mere coincidence.
In his five full seasons in the Premier League, Mourinho-managed teams have always finished in the same position they've found themselves in after 12 matches.
Three of those five seasons ended with a title triumph - we're not sure United fans would be quite as satisfied with sixth place and another season of Europa League football!