The Red Devils risk ending the season trophiless if they come out second best at Wembley Stadium on Saturday evening, having finished 19 points adrift of Manchester City in the Premier League.
United also failed to make much of an impact in the other cup competitions, suffering shock defeats to Bristol City and Sevilla in the EFL Cup and Champions League respectively.
Amid claims that this season will go down as a failure if they lose to Chelsea, Mourinho insists that the entire campaign - and whether or not it has been a success - cannot be decided by a single match.
"People can do what they want, analyse what they want to analyse," he told reporters at his pre-match presser. "I can also analyse the way I want to analyse and the way I think is fair to analyse.
"Do I consider the season good or bad because of one match, when I analyse the work I did, the effort I put, when I analyse everything we all did in the club, including the most important persons in the club - the players?
"I am not going to analyse because of one - very important - match. I know what the players did, I know the effort they put, I know the positive things and the negative things. I am not going to change my analysis of the season because of one result, not at all."
United are aiming to win their fourth trophy in three seasons at Wembley, including the FA Cup in 2016.