The fixture has not been selected for live broadcast, and falls in between Barclays Premier League clashes with Manchester United and Arsenal.
Northampton reached the second round thanks to a 3-0 victory over Blackpool, while United made it to the quarter-final stage of the competition last year, before losing to eventual runners-up Tottenham Hotspur.
Ticket details will be announced on nufc.co.uk in due course.
17 August 2015
2015-16 season tickets are on sale now. Adult tickets available from £525 and juniors from £250. Call 0844 372 1892 or visitwww.nufc.co.uk