The Hornets battled back from two goals down to stun Wolverhampton Wanderers with a 3-2 win after extra time in a dramatic semi-final.
Now, a month on from that incredible comeback at Wembley Stadium, Javi Gracia's men have the chance to make some history and end City's charge for an unprecedented domestic treble.
Ahead of Saturday's match in the English capital, Sports Mole looks at how Watford could line up.
Watford's Player of the Year Etienne Capoue got some minutes under his belt in that defeat to the Hammers following a spell on the sidelines with a groin injury, meaning that he should be available to partner Abdoulaye Doucoure in the engine room.
Gerard Deulofeu was the semi-final hero for the Hornets thanks to a couple of goals from the bench, though his place in the side is far from guaranteed this weekend. Gracia must decide whether to go with the Spaniard or Andre Gray alongside skipper Troy Deeney.
Elsewhere, cup goalkeeper Heurelho Gomes will take over from Ben Foster in goal for what will be his final game in professional football before retiring in the summer - unless Gracia can persuade the Brazilian to delay his decision until next year.