United dominated the second half but struggled to create many clear-cut chances so had to settle for a narrow 1-0 victory that sends them in to next weekend's FA Cup final against Chelsea with a morale-booting win.
Although Carrick has not featured much for United this season, it has been confirmed that he will definitely play in his sides final Premier League fixture of the season against Watford at Old Trafford tomorrow so that he can receive a fitting final send off.
And six minutes from time Mourinho was able to offer Carrick one last moment in the spotlight as he took him off, replacing him with Paul Pogba, to a massive ovation from United and Watford fans alike.
Mourinho, since the shocking Champions League defeat to Sevilla, has raised concerns over some of his players' mentality and attitude, going further to doubt whether some have the required level of quality to play for Man United.
With Martial absent, Mourinho has drafted Ashley Young into a more advanced role on the wing in a front three along with Alexis Sanchez and Marcus Rashford.
Mr Underrated. Michael Carrick, in his last ever game, continued to be just that. I've made lots of changes in the team not because of that.
But Carrick may not have been the only United player to be saying adieu to the club given yet more speculation surrounding the future of French worldwide Anthony Martial.
"I play some players that didn't play today, I play Romero, I play Daley Blind, I play Eric Bailly, I play Rashford, I play Martial, I play Mata". "I would also like to thank Manchester United and all the clubs where I have had the privilege of working during this period".
Sunday's match will be the 464 time the midfielder will have pulled on the shirt of the Red Devils having joined the club from Tottenham Hotspur back in 2006.
The former England worldwide looks to have a good opposition to go out against.
Michael Carrick won 12 major trophies during his time at Man Utd. Watford have gone seven matches away from home without scoring, so they should be there for the taking for Carrick and the United side as they finish their preparations for the cup final.