Rabbitohs fullback Alex Johnston is reportedly being closely monitored by Melbourne and Manly as his future at Redfern remains in the balance, per News Corp.

The out-of-contract winner has been in stellar form this season, but remains a chance to depart South Sydney in a move to a rival NRL club.

While there is a strong chance Johnston remains with Souths, both the Storm and Sea Eagles are now placed as serious candidates for the 25-year-old.

The Rabbitohs are preparing a monster contract for teenage sensation Joseph Suaalii for next season, with the club hoping to save enough salary space to secure the 17-year-old.

What this means for Johnston's future remains unclear.

The Rabbitohs flyer will return to face Melbourne on Friday night after sustaining a concussion against the Sea Eagles a fortnight ago, missing the club's Parramatta clash in the meantime.

With the Storm sett lose Josh Addo-Carr and Suliasi Vunivalu at the conclusion of the season, Johnston is positioned to be the perfect replacement at fullback for Melbourne.