United, who have sold their initial allocation of 1,500 tickets, have received a further 500 terracing tickets for the 7pm kick-off on Friday, July 27.
Whites' supporters have also snapped up sold around 1,000 tickets for the friendlies at Tavistock (Monday, July 23) and Bodmin (Wednesday, July 25), with all fans advised to buy in advance to avoid disappointment.
Tickets for the clash at Burton Albion on Tuesday, August 7 are also on sale.