Manchester United manager Jose Mourinho has said that he is expecting a "very difficult match" when his side welcome Watford to Old Trafford on Saturday.

United go into the game on the back of a 15-match unbeaten streak in the Premier League and knowing that victory would lift them up to fifth for a few hours at least, with Liverpool not in action until later in the day.

However, Watford have already beaten United once this season, running out 3-1 winners at Vicarage Road in September in a match that prompted Mourinho to criticise the officials and his own players after the game.

"The moments are a bit different because that moment was a period where we lost the match before, I think against Manchester City. In this case we are having I don't say the perfect results because we have many draws, but we are in the moment of being unbeatable for a long time, so we are positive," he told reporters.

"But we know that the game is going to be very difficult. This is what matters and I know that they are very difficult. They are defensive but there are teams that are very defensive but they are not well organised. They are just very defensive. That's not Watford's case. Walter [Mazzarri] is a very good coach, the team is very well-organised.

"Then they have this capacity of being dangerous in counter-attack, being dangerous in set pieces with a physical team. Many players played already in big teams. They have the knowhow, they have the experience. Many players are coming from Italian football - important clubs, Napoli, Milan, Udinese, players with great knowledge of high competition. So the team is also very experienced and I'm waiting for a very difficult match."

Watford have never won a league match at Old Trafford, drawing two and losing seven of their previous nine visits.