Neil Redfearn's side travel to the Baggies' training ground in Walsall on Monday, 23rd September.
The game was due to kick off at 2pm (BST), but it will now begin at 1pm. The match will be played behind closed doors.
United gained their first Premier League 2 victory of the season when they beat Fulham last week. They face Norwich City's second-string at Whitley Park on Monday, 16th September with a 7pm (BST) kick-off. Admission is free for season ticket holders and members, otherwise it's £3 for adults and £1 concessions.