Three minutes later, Chris Smalling put the ball in the back of the net after Fellaini's assist.
"I hope they will stay", Mourinho said when asked about that quartet.
Manchester United striker Romelu Lukaku defended Jose Mourinho's confrontational style of management, saying that the Portuguese deserves respect for not hiding his true feelings like several Premier League bosses.
"I'm very happy with the spirit, with something that represents for me the spirit of the team which is Lukaku's sliding tackle after 50 metres running back to help the team".
Rashford scored two in two games for England during the worldwide break but it was suggested by some pundits that the 20-year-old may have to leave United to further his development. "But Marouane is giving us more than that - he's giving us that but he's also giving us quality and simplicty". The Englishman is replaced by compatriot and veteran Ashley Young in what is the only change for United.
Watford at least made things interesting with a 65th-minute Andre Gray strike, but United dug deep and fended off the home side's late advances to seal the points despite Nemanja Matic's red card deep into stoppage time.
Paul Pogba, who had three first-half chances, almost doubled two minutes later, but his attempt was pushed over the crossbar by goalkeeper Ben Foster.
But now Mourinho has hit back at his critics, turning up to a pre-match press conference armed with statistics over Rashford's playing time.
Two quickfire first-half goals had Mourinho, his staff and his players every bit as delirious as the travelling army of United fans, with the general mood around the camp a far cry from what it was just a few weeks ago.
Unfortunately for Watford, that goal was not the start of a famous turnaround, and United clung on to a second consecutive victory after Matic received a second caution, De Gea denying Christian Kabasele from the resulting free-kick.
Gracia, whose side came into the match on the back of four straight wins, said his team had been outplayed in the first half but had responded well after a team talk.
"It was an easy job for Paul, because me and Javi [Gracia] didn't create any problems, but they did a very good job and if it is a yellow or not, I don't know".