Former Geelong Cat Corey Gregson and ex-Kangaroos Declan Mountford and Mitchell Hibberd headline the 22-man list set for the inaugural mid-season draft.

Having been delisted by their clubs seven months ago, Gregson, Hibberd and Mountford will all undergo medicals for AFL sides looking to add to their 2019 list.

It is understood that Melbourne has kept tabs on Gregson, who returned to SANFL club Glenelg after 39 games for Geelong.

Each club could submit up to three players prior to Wednesday's deadline for the medical screenings, in hope of finalising selections before the draft on May 22.

Clubs were to prioritise their list of draft hopefuls and were notified by the league that not every player was guaranteed to be selected to undergo medicals.

Former Dockers Josh Deluca and Brady Grey add to the list of ex-AFL nominations hoping for a second chance.

NT Thunder's Adam Tipungwuti, Coburg's Lockie Dickson and South Fremantle's Marlion Pickett headline the long list of mature-age rookie nominations.

Richmond has been strongly linked to Pickett, who was also shown interest by Collingwood ahead of last years AFL Draft.

Club's medical staff have been invited to attend the testing sessions, however, will be unable to host their own individual tests.

It is understood that clubs will look to add future talent over ready-made nominations, with 15 list spots across the league available.

Adelaide, Carlton, Collingwood, Essendon, Hawthorn, Melbourne, North Melbourne, Port Adelaide, Richmond, Sydney and Western Bulldogs all have one selection while Gold Coast and Greater Western Sydney have two spots to fill.

A number of NAB League players who impressed in last week's Young Guns series-opener are within the nominations, including Mitch Riordan (Dandenong Stingrays), Cody Hirst (Eastern Ranges) and Kyle Dunkley (Gippsland Power).

The trio were all overlooked at last years National and Rookie Drafts, with Dunkley (Son of former Sydney defender Andrew and Brother of Bulldog's Josh) being monitored by Gold Coast, Richmond, Sydney and Carlton.

While a minority of the 307 draft hopefuls who have nominated for the draft will undergo test screenings, the remaining nominations won't be ruled out of a selection.

WA Under-18's State Squad member Jarvis Pina has been shown interest by both Sydney and Fremantle, with the Dockers currently unable to make a selection on draft day.

Clubs like Fremantle who are unable to make a selection at the Mid-season Rookie Draft would have an open spot if the club were to suffer a long-term injury or lose a player to retirement.

Mid-Season Draft Medical Testing List:

Ajang Ajang (East Perth)
Frank Anderson (Northern Blues)
Daly Andrews (Western Jets)
Ray Connellan (Essendon VFL)
Josh Deluca (Subiaco)
Lochlan Dickson (Coburg)
Kyle Dunkley (Gippsland)
Oliver Eastland (Claremont)
Cory Gregson (Glenelg)
Brady Grey (West Coast WAFL)
Mitch Hibberd (Williamstown)
Cody Hirst (Eastern Ranges)
Lachlan Hosie (Glenelg)
Sam Lowson (Coburg)
Jack Mayo (Subiaco)
Declan Mountford (Claremont)
John Noble (West Adelaide)
Matt Nunn (Norwood)
Marlion Pickett (South Fremantle)
Jarvis Pina (Peel Thunder)
Mitch Riordan (Dandenong)
Adam Tipungwuti (NT Thunder)