It's understood the Panthers' salary cap situation for 2022 and beyond is dire, and clubs are circling for the duo.
The Daily Telegraph are reporting the Panthers still have five spots to fill for 2022, and that the price tag of Staines and Leniu - who are both on roughly $300,000 - could be too much for the club to handle.
The Panthers' push for a premiership this year saw them sign Tevita Pangai Junior, despite previous rumours they were going to use the cap space to forward pay some contracts for 2022.
While the duo are being circled, and the Panthers may want to let them go, Leniu is on contract until the end of 2023, while Staines is tied to Penrith for the same time frame.
It'll make negotiations complex, with the duo both touted for big things in the Penrith system, which is chock full of young stars.
The news of the potential exits comes just days after Penrith CEO Brian Fletcher said the Panthers were confident of hanging onto all of Dylan Edwards, Apisai Koroisau and Viliame Kikau.
It had been previously thought that Kikau's position at Penrith was almost certainly going to be gone, while Koroisau and Edwards' future was up in the air.
All three players will be requiring salary cap upgrades of some description to stay at Penrith for 2023 and beyond, which will only squeeze the Panthers further for years to come.
Given Leniu and Staines are both on contract for 2023, Penrith being possibly willing to move them on will be a two-fold play, and one which could potentially make sense, given Staines' drop off in form this year and Leniu's battle for game time behind James Fisher-Harris, Moses Leota and others.
Staines wasn't named for this Saturday's preliminary final against the Melbourne Storm, while Leniu was amongst the reserves and has since been called into the 17 following the withdrawal of Moses Leota as the Panthers hunt for a spot in their second straight grand final.