The game will kick-off at 7.45pm.
The Hatters reached this stage of the competition after winning both of their opening two Southern Group H fixtures against Brighton & Hove Albion Under-21s and Milton Keynes, before a defeat in the final game against Peterborough.
The Shrimpers finished second in Southern Group B, as they won two of their games, but missed out on top spot on goal difference, in a group that included Cambridge United, Colchester United and Southampton Under-21s.
Ticket prices for the game at Kenilworth Road are as follows:
Adults/Concessions: £5Under-16s: £1