The tournament is unpopular with fans, with attendances being in the hundreds rather than thousands.
The first two in each group qualify for the knockout stages, which are now national rather than regional, from the third round onward.
The eight winners of the Northern and Southern sections will be at home to one of the eight runners-up from the same section, but not the team who finished second in their group, in the second round.
The sixteen winners go forward to round three which is unseeded and national.
Theoretically the groups should be localised so that journeys for travelling fans are reduced. But Swansea Under-21s are in the same group as the Addicks, Wimbledon and Stevenage.
Clubs are required to field four qualifying players – effectively first team regulars. With the injury situation as it is, it would be no surprise if Charlton failed to meet the criteria and opted to be fined.
To further complicate matters, Jason Euell’s Under-23 side played on Monday in a 1-1 draw with Nottingham Forest.
Another slight variation to the normal cup format is that if a game is level after 90 minutes, it goes to a penalty shoot-out with the victors picking up a bonus point.
Jed Steer is likely to make his first appearance for the Addicks, but it is almost impossible to predict who else might be involved. Kevin Johnson will be the referee.
Only the West Stand will be open for Charlton fans, away fans will be housed in the Jimmy Seed Stand as usual.
Stevenage beat Swansea Under-21s 5-0 last week in the opening match in the group.