Indeed, Watford have collected 12 points from their four league fixtures this term, and will be looking to overcome a United team that has won two and lost two of their four matches during a tough start to the season.
It was supposed to be a tough campaign for Watford, and while that still might be the case, the Hornets have made a stunning start to the season, with four wins from four matches seeing them put 12 points on the board.
Javi Gracia's outfit are one of only three teams - the other two being Liverpool and Chelsea - to have a 100% record at this stage, and another victory this weekend would leave the Watford fans dreaming of a potential 'Leicester City season'.
The Hornets opened their 2018-19 campaign with a 2-0 win over Brighton & Hove Albion, beat beating Burnley and Crystal Palace in their next two in the league ahead of a 2-0 victory over Reading in the EFL Cup.
Watford were tipped to come unstuck against Tottenham Hotspur before the international break, but they came from behind to record a 2-1 win over Mauricio Pochettino's side to make it their best-ever start to a Premier League campaign.
Gracia's team finished 14th in the Premier League last term, and were not particularly busy during the summer transfer window. Something has clicked in the early weeks though, and they will be full of confidence ahead of the visit of United.
Watford dropped points in 12 of their 19 home Premier League matches last season, however, and have lost 20 of their 30 matches with United in all competitions, recording just five wins.
The Hornets have only beaten the Red Devils once since 1986, although that was a 3-1 success at Vicarage Road during the 2016-17 Premier League season, and the club's supporters will be eyeing another success this weekend.
Recent form: WWWW
Recent form (all competitions): WWWWW
United opened their 2018-19 Premier League season with a 2-1 win over Leicester on August 10, but back-to-back defeats to Brighton & Hove Albion and Tottenham Hotspur saw things go south pretty quickly.
Indeed, United's back four was all over the place in the 3-2 defeat to Brighton on August 19, before a 3-0 home loss to Tottenham on August 27 led to speculation that Jose Mourinho could lose his job as head coach.
Mourinho eased the pressure with a 2-0 success away to Burnley before the international break, but the 20-time English champions are already six points off the top of the table, and that could become nine this weekend.
Only the champions Manchester City had a better away record than United in the Premier League last season though, and as mentioned above, the Red Devils have a very strong set of results against Watford.
United are entering an interesting set of fixtures as they open their Champions League group campaign away to Young Boys on Wednesday night, before hosting impressive Wolverhampton Wanderers in the Premier League next weekend.
Mourinho's side will then host Derby County in the EFL Cup before visiting West Ham United in the league on September 29. The 2018-19 campaign is in full swing, and the Red Devils really need to put a strong run of results on the board.
Talk of Zinedine Zidane replacing Mourinho as head coach has gathered pace in recent weeks, but things can change in football pretty quickly, and a strong end to September would leave United in a much stronger position.
The English giants have only lost one of their 10 Premier League meetings with Watford, and despite the Hornets making a very impressive start to the campaign, Mourinho will be confident of leading his team to another away success on Saturday night.
Recent form: WLLW
Head coach Gracia could keep with the same XI that started against Tottenham last weekend, although Andre Gray could drop out if there is a change of formation, with Nathaniel Chalobah potentially coming into midfield.
Troy Deeney was on the scoresheet against Spurs last time out, and will look to cause a fragile United defence problems.
Marcus Rashford will miss out for United after the forward, who netted twice for England during the recent international break, picked up a straight red card in the win over Burnley last weekend.
Phil Jones is also still unavailable for the Red Devils, while Luke Shaw is unlikely to feature despite not yet being officially ruled out of the match with the head injury that he suffered in England's 2-1 defeat to Spain.
As a result, Ashley Young should be handed his first start of the season at left-back. Summer arrival Diogo Dalot is also in contention, while Marouane Fellaini's impressive performance against Burnley could see the midfielder keep his spot, although he will need a late fitness test on a back problem.
Watford possible starting lineup:
Foster; Janmaat, Cathcart, Kabasele, Holebas; Capoue, Doucoure, Chalobah; Pereyra, Deeney, Hughes
Man United possible starting lineup:
De Gea; Valencia, Lindelof, Smalling, Young; Fellaini, Pogba, Matic; Sanchez, Lukaku, Lingard
Head To Head
Saturday will be the 31st meeting between Watford and United in all competitions. United have won 20 of the previous 30, suffering just five defeats.
As mentioned, United have won nine of their 10 Premier League meetings, including a 4-2 victory at Vicarage Road last season.
Watford's 3-1 home success during the 2016-17 Premier League season was the first time that they had beaten the Red Devils since September 1986.
We say: Watford 1-2 United
Watford will enter the match full of confidence following a very strong start to the season, but United were impressive against Burnley, and we fancy the Red Devils to record a narrow victory at Vicarage Road.