Manuel Pellegrini's side have only lost once this season and must fancy their chances against a United side whose midfield and attack has fallen short of expectations so far this term.
West Ham United
Aside from an opening weekend 5-0 drubbing at the hands of Manchester City, West Ham have demonstrated a level of tactical acumen and overall technical ability which suggests that they will not, unlike in previous years, spend this season battling relegation.
The club has recognised the importance of continued evolution on the pitch, and the sale of key attacking duo Marko Arnautovic and Javier Hernandez, combined with the signing of Sebastian Haller for £36m, is a sign of the club refusing to stand still after finishing in a respectable 10th place last season.
Indeed, perhaps the most important position in which one needs to start well at this level is the number nine role, and Haller has done exactly that, scoring three goals from his opening four matches in England - including a brace during a 3-1 win away at Watford.
When it comes to setting yourself apart from teams battling it out at the bottom, the key variable is how precise your football can be in the final third, how regularly you can pin the opposition back around their own box.
Monday's 0-0 draw at Aston Villa, despite not yielding any goals, was a good illustration of how West Ham possess a level of technical nous which the Midlands side, for all their efforts, do not have the requisite quality to replicate.
Specifically, the nimble duo of Manuel Lanzini and Felipe Anderson, two South American attacking midfielders, combined with the sharp shooting of Andriy Yarmolenko, have given West Ham a certain stylistic edge when taking part in games like the 2-0 home win over Norwich City last month - a relatively even affair ultimately won over by West Ham's superior ball retention in the last third.
The Irons have worked hard to address this attacking midfield area since the fallow period which followed Dimitri Payet's departure, and will feel that the aforementioned trio hold the key to causing United's understaffed midfield a number of problems.
Pellegrini's men only need to look back to almost exactly one year ago, a 3-1 home win over United, during which Jose Mourinho's men were simply overrun by a more energetic team, to know that these players have the knowhow and confidence to expose the shortcomings of their visitors this weekend.
Recent form: LWDWD
Recent form (all competitions): DWWWD
United have responded in the right way to going three games without a win prior to the international break, claiming 1-0 victories over Leicester City and Astana - games in which they were hardly troubled defensively.
However, despite a much-needed pair of victories, the same worrying questions regarding the quality of their midfield and attack continue to linger for Ole Gunnar Solskjaer, who will be privately concerned at his team's lack of bite since the opening day 4-0 win over Chelsea.
Since that victory, United have only managed one goal per game, and had to rely on the prodigious talent of 17-year-old Mason Greenwood to find an opening after 70 minutes against Kazakhstani side Astana - a team you would expect any of the top six to roll over quite comfortably.
Despite the team against Astana comprising almost entirely of academy players or rusty squad members, two problems which have impeded United for some time were still there to see: an inability to break down teams playing a low block and a failure to score what Solskjaer calls "scruffy goals".
Marcus Rashford, for example, squandered a pair of excellent close-range chances in the box which came to him quickly, with Solskjaer noting after the game that the 21-year-old ought to have used his left foot rather than his right for a shot saved by Nenad Eric. The Englishman has not scored from open play in five games now.
At the London Stadium, United will be granted more space in the opposition's half compared to what was on offer against Leicester and Astana, giving them an improved chance to play the counter-attacking football which has come to be associated with this Solskjaer regime.
What could trip United up, however, is the agility of Anderson and Lanzini up against the creakiness of their midfield, which came in for heavy criticism against Southampton and was put under seige in the second half against Leicester last weekend.
If West Ham, as expected, decide to attack this United team from the start, the result will be largely determined by how well the likes of Scott McTominay and Fred can soak up pressure and shift it back onto the home side by unleashing its counter-attacking style - which, as seen in that second period against Chelsea, can be very effective when it works.
Recent form: WDLDW
Recent form (all competitions): DLDWW
Pellegrini confirmed in Friday's press conference that Lanzini had suffered a knock during the week and would be assessed tomorrow ahead of the club making a late decision on his fitness.
Michail Antonio is not set to return from a thigh injury until next year, while defender Winston Reid is expected to come back into the fold next week. Arthur Masuaku is suspended for the game after receiving a questionable red card at Villa Park on Monday.
For United, Solskjaer continues to be without Paul Pogba, who suffered an ankle injury before the international break, with the Norwegian also confirming on Friday that Anthony Martial and Luke Shaw were still out.
Eric Bailly and Timothy Fosu-Mensah are the two long-term absentees, although Solskjaer did claim that he was "hopeful" of Daniel James returning after the Welshman missed the win over Astana due to a knock.
West Ham United possible starting lineup:
Fabianski; Fredericks, Diop, Ogbonna, Zabaleta; Rice, Noble; Yarmolenko, Lanzini, Anderson; Haller
Manchester United possible starting lineup:
De Gea; Wan-Bissaka, Lindelof, Maguire, Young; McTominay, Fred, Pereira; Lingard, Rashford, Greenwood
Head To Head
There used to be a time when United would view trips to West Ham with no trepidation at all, enjoying an unbeaten run in the Premier League at Boleyn Ground between 2007 and 2016, when the Hammers beat United 3-2 in their final game at the stadium.
Now, however, the new ground feels like a place where anything can happen, with United claiming one win, one draw and one defeat in their three visits to the London Stadium.
That said, United can nonetheless claim supremacy when it comes to encounters with West Ham overall, winning 33 of the 56 games against the Irons in the Premier League era.
West Ham will be unconcerned by that record, and instead can take confidence from beating them comfortably last year as well as deserving much better than a 2-1 defeat at Old Trafford back in April.
We say: West Ham United 2-1 Manchester United
United are still without an away win since that 3-1 success in Paris six months ago, and if their recent displays at Wolverhampton Wanderers and Southampton are anything to go by, they have a genuine problem when it comes to starting well before trailing off.
Should they score and then take their feet off the gas against Pellegrini's men, the likes of Anderson and Haller will no doubt be on hand to punish a Solskjaer team whose midfield is failing to control games from start to finish.
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