The four regional groupings and first-round byes have been announced ahead of the start of this year's Football League Trophy.
32 of the 48 sides from League One and League Two will take part in the first round later this month, while 16 have been handed byes.
Wigan Athletic and Blackpool, who were both relegated from the Championship last season, are in the North (West) group, but both receive byes.
However, Millwall, who also dropped down from the second tier, will have to play in the first round in the South (East), where they could be drawn against the likes of League Two sides Cambridge United or Luton Town.
The two sides promoted from the Conference Premier will both take part in the South (West) grouping, but playoff winners Bristol Rovers have a bye, while champions Barnet must play in round one.
Cup holders Bristol City will not return to defend their title, having won promotion to the Championship last season.
The draw for the first round of the competition will be held on Saturday.
Football League Trophy groupings and byes in full:
North (West)
Accrington Stanley
Bury
Carlisle United
Morecambe
Oldham Athletic
Port Vale
Shrewbury Town
Walsall
Byes: Blackpool, Crewe Alexandra, Fleetwood Town, Wigan Athletic
North (East)
Barnsley
Burton Albion
Doncaster Rovers
Hartlepool United
Mansfield Town
Notts County
Scunthorpe United
Sheffield United
Byes: Bradford City, Chesterfield, Rochdale, York City
South (West)
AFC Wimbledon
Barnet
Exeter City
Newport County
Plymouth Argyle
Portsmouth
Swindon Town
Yeovil Town
Byes: Bristol Rovers, Coventry City, Oxford United, Wycombe Wanderers
South (East)
Cambridge United
Colchester United
Dagenham & Redbridge
Leyton Orient
Luton Town
Millwall
Northampton Town
Peterborough United
Byes: Crawley Town, Gillingham, Southend United, Stevange