Manchester United manager Jose Mourinho has criticised Luke Shaw's role in Watford's second goal at Vicarage Road on Sunday afternoon.
Moments after coming off the bench, Juan Zuniga put the Hornets into a 2-1 lead before Troy Deeney's last-minute penalty gave Walter Mazzarri's team a surprise win.
Mourinho later suggested that his team had been "punished" by errors made by the officials but one of his own players did not escape criticism in his post-match assessment.
The 53-year-old is quoted by The Mirror as saying: "Here for the second goal, Amrabat receives the ball and our left-back is 25 metres from him instead of five metres. But even at 25 metres, you have to jump and go and press, but no, we wait.
"This is a tactical but also a mental attitude. It's something that doesn't become perfect in a couple of weeks."
United have slipped down to seventh position in the standings as a result of the defeat.