The Hammers travel to the Leigh Sports Village for the 7 pm clash after beating United 4-2 in the east end last October.
Victory would see Westley’s men complete their first league double of the season and the boss is looking forward to the challenge.
He said: “We have been very competitive in Division 1 this campaign and have managed to get 17 points in eleven games.
“Clubs stayed up last season with 23 points, so we’re in a really strong position at this point having achieved notable wins over Manchester United already, as well as City, Spurs and draws against Chelsea and Everton.
“It shows how competitive we can be; we can compete with the very best teams in this league when we field a strong XI and that’s what we want to do on Monday.
“The challenge from now will be to go on to accumulate as many points as possible to finish the season strongly although we know that challenge will be tough.”