Fremantle have signed former Essendon forward Patrick Voss via the Supplemental Selection Period.

Voss has been one of four train-on prospects at Cockburn, joining Juston Longmuir's ranks in late November - just months on from his departure from the Bombers.

The key forward was delisted by Essendon after two years in the red and black, with the 20-year-old going without an AFL debut but did manage to claim a VFL best and fairest gong last year.

In a bid for an AFL lifeline, Voss has trained alongside fellow SSP prospects Daniel McKenzie, Sam van Rooyen and Max Beattie at the Dockers, who have a pair of list spots available.

On Thursday the Dockers confirmed Voss won a contract following an impressive summer stint in Western Australia.

“He's trained well all summer and has kicked goals in our match sim in the past two weeks,” Dockers list manager David Walls said.

“He's forced his way onto our list with output and attitude.

“We don't have a huge amount of key forwards on our list and he fits a list management need.”

The signing of Voss comes as Longmuir looks to settle on his key forward stocks for 2024 and beyond, with a partner for young sharpshooter Jye Amiss yet to emerge.

Fremantle train-on player Patrick Voss at Dockers pre-season training, 2023 (Image via Twitter, Fremantle FC)

Ruck-forward hybrid Josh Treacy looms as a Round 1 chance to pair with Amiss, with Matt Taberner working his way back from a luckless run with injury.

Duo Josh Corbett and Sebit Kuek have both been placed on the club's inactive list, opening up list spots for the club to trial SSP hopefuls.

Walls thanked Beattie, McKenzie and van Rooyen for their time with the club.

“They all showed AFL qualities with their attitudes and appetite for work,” Walls said.

“Unfortunately, Dan was injured during his time at Fremantle and we wish him well.

“Max and Sam did the whole pre-season and should be commended on their outstanding summers.

“We'll watch them closely and hopefully they will force themselves onto AFL lists.”

Clubs can choose to leave list spots open in favour of carrying a list vacancy through to the Mid-Season Draft.

Collingwood finalised their list on Thursday with three SSP signings, while Richmond are yet to make a decision on their pair of prospects.

Gold Coast and North Melbourne also have free list spots but do not have train-on members.