"It pains me to say this, as my mum's side of the family support City and I used to play for Liverpool, but how can you knock United when they have secured second place in the table and reached the FA Cup final?" Carrick's 464th appearance for United ended in the 85th minute when he left the game to a huge ovation.
Faria announced on Saturday evening that he will step down as his Portuguese compatriot's right-hand man this summer, bringing an end to their 17-year association.
And Watford's inability to take advantage of United's lackadaisical start was punished as Carrick provided a wonderful flourish of creativity to mark his last game. David De Gea will be rested, so it gives a chance for Sergio Romero to play.
The 25-year-old has, however, returned to form of late - landing United's Player of the Month award for April - and believes heated exchanges with his manager can actually be a positive thing.
Eric Bailly and Daley Blind have also returned to the starting line-up with Marcos Rojo and Matteo Darmian.
"I've got some unbelievable memories to cherish".
"Carrick is going to start the match as captain but he is not going to end the match because I want him to leave that pitch alone".
United are also reportedly in the market for a central defender and have been linked with Barca centre back Samuel Umtiti, who now in the midst of a contract standoff with his club.
It was a special moment on an emotional day.
Herrera described Carrick as one of the best midfielders of the last decade and hopes United can deliver a "beautiful" send off for him. In his 12-season stint at Old Trafford, he has lifted the Premier League five times, while also winning one FA Cup, three League Cups and two European trophies, including the 2008 Champions League.
Herrera believes the former England worldwide has all the attributes to succeed in a managerial role in the future.