The Premier League has virtually been wrapped up by rivals Manchester City, who can restore their 16-point lead at the summit with a win over Stoke on Monday, and the EFL Cup has already been decided in the 'Sky Blues' favour too.
It leaves the FA Cup, which United will battle out with Brighton & Hove Albion for a place in the semi-finals at the weekened, and the Champions League for Mourinho and his players, who will undoubtedly aim for European glory after lifting the Europa League last season.
That trophy followed success in the League Cup, securing the Portuguese manager two trophies in his first year in Manchester, and pressure will be on to repeat that feat this campaign.
The 'Red Devils' will be one of the favourites for the FA Cup, along with Tottenham and Chelsea, but winning the trophy will not be enough to satisfy the board or the supporters unless it is teamed with a second-placed finish in the league and success in Europe.
After 0-0 in the first leg, the tie is finely poised for both teams with United arguably having the advantage given that the second fixture will be made in their stadium.
However, Sevilla won't make it easy for the Manchester club and will be looking to Steven Nzonzi, who has previous experience playing in England, to cause an unlikely upset on Tuesday.
Furthermore, if United do manage to progress, there's a good chance that they will be handed a difficult draw with Real Madrid, Manchester City, Liverpool and Juventus having already secured their places in the quarter-finals and Bayern Munich almost guaranteed theirs after winning their first leg 5-0.