However, following the victory, the 55-year-old revealed (via the Daily Mail) that his soon-to-be former player will have to be patient in his new career.
Speaking to reporters after the match, according to the Guardian, Carrick expressed his gratitude towards United boss Jose Mourinho, who has chose to offer him a coaching role at the club, with a view of making him his number two in the near future.
Carrick is set to join Mourinho's backroom staff and could be more involved than first thought following the shock announcement that Rui Faria is leaving the club.
Michael Carrick says he's happy to give Jose Mourinho his opinion on Manchester United transfer targets this summer as the Red Devils gear up for a crucial transfer window. And my analysts. I'm not going to have an assistant manager in the sense of the word. It is an unbelievable opportunity.
"He's one of the best".
"I will organise my coaching staff in a way where the assistant manager figure doesn't exist", Mourinho said.
He said: "You've got to go step by step".
"Also, in the second major competition in the country, we are one of the two best teams; we are playing the [FA Cup] final so if you want to read it in a positive way, you can in a very objective way".
"I have a lot of memories to cherish, some I'll never forget, especially of this place".
United still have the FA Cup final to play this weekend, but it's unlikely that any of the players who appear at Wembley will be allowed to leave the club by Jose Mourinho.
The tweet read: "Carrick, awesome person and sensational player. It's the manager having the faith to play me that's been incredible and I can't thank him enough".
'He was injured in the Friday training session and yesterday (Saturday) he couldn't train. "He had treatment in the morning in the training ground and stayed away".
Watford: Gomes, Janmaat, Cathcart, Kabasele (Mariappa, 20 mins), Holebas, Doucouré, Hughes, Deulofeu (Deeney, 63 mins), Pereyra, Richarlison, Gray (Chalobah, 72 mins).