AFL.com.au understands Hardingham's management group has notified rival clubs of the 26-year-old's desire to find a new home.
Essendon is believed to be aware of Hardingham's intentions, after the versatile Bomber played just eight games in each of the past two seasons.
The decision is based purely on the player wanting better prospects of playing senior football.
Hardingham was picked by the Dons in the 2010 NAB AFL Preseason Draft, and started his career as a high-leaping forward.
He moved to defence soon after and found his niche in 2011, playing 22 games and another 21 in 2012.
Hardingham signed a one-year contract extension in 2013 through to the end of 2014, and is a popular member of the Bombers, having been voted best team player last season.
He played the first six games of this season as a forward, and kicked nine goals in the opening four rounds, but last played in the senior side in round 16 despite strong VFL form, for a total of 65 games with Essendon.
The Bombers are going through their end-of-season reviews with players this week, with Martin Gleeson and Ben Howlett among the group of players unsigned for next year.
A decision on veteran Dustin Fletcher's future is also expected soon.
The club announced on Tuesday that development coach James Byrne would depart Essendon after three seasons in the role.