The 24-year-old featured for the Panthers last weekend after returning from his loan deal at the Warriors, with Hetherington now in high demand after being given permission to source a new club.
The Warriors and Canterbury are also in the mix for the aggressive prop, who has one year left on his deal with the Panthers.
It is understood that the Warriors are set to miss out on Hetherington due to his desire to remain in Sydney, leaving the battle for his signature between the Sea Eagles and the Bulldogs.
Canterbury may hold a slight edge as Penrith assistant Trent Barrett
will join the club next season.
However Manly are hoping to persuade him, where a potential partnership with Marty Taupau would make things interesting due to their recent history.
Hetherington was charged with a grade three careless high tackle last month for a shot that knocked out Taupau and left the Sea Eagles prop with short-term memory loss.