After an off-season of speculation, chief executive Dave Donaghy has confirmed Addo-Carr has been dealing with personal challenges that require him to relocate to Sydney in the long term.

However, in order to grant the State of Origin flyer a release on compassionate grounds, Storm has stipulated a list of strict conditions including a transfer fee, player swap or salary cap relief.

Addo-Carr is contracted to the club until the end of 2021, but has had a rapid upswing in his career since arriving from the Wests Tigers in 2017.

In the three seasons since moving south, the 24-year-old has earned NSW and Kangaroos jerseys and established a reputation as one of the best wingers in the NRL.

And now it appears Storm won't let him go without adequate compensation.

In a letter to fans on the club website, Donaghy stated a swap would need to be with a player of "commensurate standing", while salary cap relief would be for: "doing the right thing by the player and providing some extra support for Josh, not dissimilar to the recent scenario in the AFL with Tim Kelly at the Cats."

Geelong fought to keep Kelly but eventually he was released to West Coast for high draft picks in 2020.

"We believe this would be a fair outcome for all parties given the investment the Storm has made in Josh and that we find ourselves on the cusp of the 2020 season," Donaghy said.

"Most importantly, it would allow Josh's request to be met and we, and the game, would be able to continue to support him and his family in the transition back to Sydney."

Addo-Carr's release would leave Storm without their two strike wingers with Suliasi Vunivalu also to depart the club at the end of the season.

Australian Associated Press