The Hammers face Manchester United and could - albeit for a short spell of time - climb to fifth in the Premier League with a win.
Moyes has made just five changes to his starting line up for Premier League games all season, with the consistent side bringing about a strong start to the campaign - and Haller has settled in since Antonio's injury problems.
"I think that in games we have had, this period, we have been consistent," said Moyes. "Yes there have dips but most teams will do that. I hope the consistency improves for the next period and to keep a level of it where we think we will be, where we can build on it and at the moment that is what we are trying to do.
"I am trying to get the players to understand there is a level of performance required and hopefully, when we don't play as well, we have resilience to get us points."
West Ham XI: Fabianski, Balbuena, Ogbonna, Cresswell, Coufal, Rice, Soucek, Masuaku, Bowen, Fornals, Haller
Subs: Benrahma, Lanzini, Snodgrass, Noble, Diop, Johnson, Randolph
Man Utd XI: Henderson, Wan Bissaka, Lindelof, Maguire, Alex Telles, McTominay, Pogba, Greenwood, van de Beek, Martial, Cavani
Subs: Mata, Rashford, Grant, Bruno Fernandes, Matic, Williams, Tuanzebe
Saturday 5.30pm, Sky Sports
Venue: London Stadium
Referee: Andre Marriner
Last meeting: Manchester United 1-1 West Ham
West Ham squad from: Fabianski, Randolph, Martin, Balbuena, Diop, Ogbonna, Dawson, Coufal, Johnson, Cresswell, Masuaku, Noble, Rice, Soucek, Fornals, Snodgrass, Lanzini, Yarmolenko, Benrahma, Bowen, Haller
Injured: Antonio (hamstring)
This weekend get a £10 free bet with Betfair, when you bet £10 on a Same Game Multi on the Premier League.
Terms: Min £10 Same Game Multi bet on any EPL match this Fri - Sun. Free bet valid for 72 hours, awarded at bet settlement. Excludes cashed out bets. T&Cs apply.