Prominent player agent Peter Jess says clubs should do anything in their power to tempt the best players to join them, as Essendon star Brendon Goddard branded the approaches to top Bombers as "unethical".

Jess, a player manager for more than 30 years, says list managers from rival clubs were compelled to explore a "once-in-a-generation opportunity" to strengthen their lists with ready-made players from Essendon without giving up their own players or draft picks.

Essendon's Brendon Goddard. Credit:Wayne Taylor

Jess, who does not represent any Essendon players, says agents who do have Bomber clients were obliged to seek their player's market value having been presented with an unprecedented environment in which to do so.

Goddard spoke out against those clubs who sought to benefit from Essendon players using the mismanagement of the 2012 supplements program as the basis to trigger a duty-of-care clause that would allow them to break their contracts and walk for essentially nothing.