Manchester United have reduced Old Trafford's capacity by 12,000 for next Wednesday's Carabao Cup fourth-round tie with Burnley because of an ambulance strike taking place on the same day.
Manchester United say that option was not open to them for several reasons, including the "unavailability of other key public services and matchday staff over the Christmas period".
The club confirmed West Stand tier two and North Stand tier three will be closed, leaving the tie with a 62,000 capacity.
As the match is a sellout, the club say they will contact those affected and offer refunds.