Man Utd have released their ticket details for the FA Cup semi. Their allocation is 33,411, so surely we should get that too?
http://www.manutd.com/en/Tickets-And-Hospitality/Tickets-And-Hospitality-News/2018/Jan/FA-Cup.aspx
http://www.manutd.com/en/Tickets-And-Hospitality/Tickets-And-Hospitality-News/2018/Jan/FA-Cup.aspx