Jake Niall from Fox Sports has reported that the 27-year-old, who is from Western Australia, has been offered a five-year deal to join the Dockers from 2017.
Hooker is a restricted free agent, meaning the Bombers will have an opportunity to match any bid Fremantle make for Hooker.
The offer is said to be large enough that it would earn the Bombers a first round compensation pick.
Hooker is one of 34 past and present Essendon players currently serving a 12-month doping ban.
— FOX FOOTY LIVE (@FOXFootyLive) February 29, 2016