O'Sullivan has rekindled some impressive form in recent weeks to further stamp his place as the Warriors' leading halfback in the absence of Chad Townsend.
The Sharks' interest is understood to be in the form of a loan signing however, with Townsend's fitness likely to impact whether the Warriors depart with O'Sullivan on a part-time deal.
Without a contract for the 2022 season, O'Sullivan could use a short spell on the Shire as a potential dress rehearsal for incoming Cronulla coach Craig Fitzgibbon, who could look to add to his half stocks for next year.
The Sharks are yet to identify who will partner incoming recruit Nicho Hynes, but have re-signed veteran five-eighth Matt Moylan for a further 12 months.
It seems Cronulla will also be looking to add to his forward pack for next season, with Gosiewski tipped to be on their radar as a potential acquisition.
The Sharks have added forward duo Dale Finucane (Melbourne) and Cameron McInnes (St George Illawarra) to their 2022 list alongside Hynes in what has been a stellar recruitment drive for Fitzgibbon's maiden senior coaching season.
Gosiewski has battled a foot injury this season, which - along with form - has limited him to just six matches in an off-contract campaign.
The 27-year-old has played just 46 games in four seasons for the Sea Eagles since switching from South Sydney at the end of the 2017 season.