Jake Kolodjashnij in action against North Melbourne in round five, 2011. Picture: AFL Photos

GEELONG defender Jake Kolodjashnij is on the verge of a fresh contract extension that will wipe him off this year's free agency list.

AFL.com.au understands the 25-year-old is working towards a new three-year deal to tie him to the Cats until at least the end of 2024.

Kolodjashnij this year qualified as a restricted free agent, meaning he sits inside Geelong's top 25 per cent of paid players in 2021.

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The Tasmanian has been one of the Cats' most reliable defenders in recent years and one of backline coach Matthew Scarlett's first-choice players when available.

The 193cm Kolodjashnij missed three games earlier this season with a knee injury but has since returned to play a crucial role with Mark Blicavs moving higher up the ground.

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His looming signature will reduce the list of available restricted free agents to five – Matt Crouch (Adelaide), Zach Merrett (Essendon), Josh Kelly (GWS), Jack Billings (St Kilda) and George Hewett (Sydney).

Carlton co-captain Patrick Cripps is yet to formally ink a new deal but has been in protracted talks with the Blues in recent weeks. Western Bulldogs skipper Marcus Bontempelli was also set to qualify but last week penned a four-year deal.

Kolodjashnij has played 118 matches for the Cats and holds the longest active streak in the competition for games without a goal.

Other key Cats out of contract at season's end include Gary Rohan, Rhys Stanley, Brad Close, Tom Atkins, Gryan Miers and unrestricted free agents – Joel Selwood, Jed Bews and reigning best and fairest Cam Guthrie.