MELBOURNE, AUSTRALIA - MAY 13: Jack Billings of the Saints celebrates kicking a goal during the round eight AFL match between the St Kilda Saints and the Carlton Blues at Etihad Stadium on May 13, 2017 in Melbourne, Australia. (Photo by Quinn Rooney/Getty Images)

Jack Billings' latest setback has sparked fears his tenure at Moorabbin has already seen his final game in the red, white and black transpired.

Billings, a restricted free agent, is set to miss the next few weeks of action after sustaining a hamstring strain at training this week.

The injury places the remainder of Billings' 2021 campaign in doubt, especially if the Saints fail to land a top-eight placing by the end of the home and away season.

With just three matches remaining, the Saints sit in 13th on the ladder and four points outside of a finals spot, with Billings now tipped to miss upcoming games against the Swans and Cats, as well as being in an uphill battle to face Fremantle in Round 23.

Contract discussions between Billings and the Saints are still ongoing, meaning Friday's loss to Carlton may have been his 144th and final game with St Kilda should a new deal fail to eventuate.

Billings is understood to be keen to remain at Moorabbin, with that feeling mutual from St Kilda, however agreed terms are yet to be seen as talks progress between the two parties.

LAUNCESTON, AUSTRALIA - APRIL 28: Jack Billings of the Saints kicks the ball during the 2018 AFL round six match between the Hawthorn Hawks and the St Kilda Saints at UTAS Stadium on April 28, 2018 in Launceston, Australia. (Photo by Michael Willson/AFL Media/Getty Images)

Should a rival suitor offer the former Oakleigh Charger a substantial offering the Saints won't look to compete with, Billings could land at a new club and leave the Saints with compensation - a similar scenario that saw Brad Crouch depart Adelaide for St Kilda last year.

Billings joins the likes of Seb Ross, Luke Dunstan, Jake Carlisle, Jarryn Geary and Darragh Joyce in being out-of-contract at St Kilda this season.

The Saints onballer is one of only four restricted free agents remaining this season, with Giants superstar Josh Kelly, Crows midfielder Matt Crouch and Swans utility George Hewett also falling into the category.