The Red Devils ended the Premier League season 11 points better off than their opponents and are chasing a record-equalling 13th success in the world's oldest cup competition.
Here, Sports Mole looks at the starting lineup the Portuguese could field this weekend.
Doubtful: Anthony Martial, Romelu Lukaku, Marouane Fellaini
As noted by Chelsea midfielder Cesc Fabregas earlier in the week, Mourinho loves springing a selection surprise against the Blues, most famously using Ander Herrera to man-mark Eden Hazard out of the game last season.
Mourinho could also mirror Antonio Conte's formation by going with three at the back, but that is a risky strategy and may play into Chelsea's hands.
A back four is therefore more likely, with Eric Bailly in contention to feature from the off despite starting just two games since the last international break in March - the most recent of those outings, quite tellingly, coming against Watford last weekend.
The Red Devils are still sweating over the fitness of Lukaku up top, as the Belgian only returned to training on Tuesday following more than two weeks on the sidelines.
Martial is another injury doubt, being left out of the squad entirely to face Watford, but both Alexis Sanchez and Jesse Lingard are fit, as is Marcus Rashford, who netted the winner for his side in their last outing.