Geelong Cats' Sam De Koning. Photo: Michael Wilson, AFL Photos

Geelong have reportedly begun discussions with emerging star Sam De Koning in regards to a new contract, with the premiership defender said to be in line for a large pay increase.

De Koning enjoyed a breakout campaign with the Cats this year in what was his first full season at AFL level, often taming the opposition's best tall forward on his way to Geelong's grand final win over Sydney.

The 21-year-old recommitted with the Cats last year, extending from his rookie deal until the end of the 2023 season prior to making his AFL debut.

The 200cm-tall backman is now expected to ink another extension, with Geelong moving to secure their prized young star until at least the end of 2025, according to News Corp.

That deal is said to earn De Koning up to $600,000 per season, a sum the Mt. Martha product is sure to be worthy of in the coming years.

The move from Geelong is also one that will stave off rival interest before De Koning reaches a period where he'd begin discussing his future with potential suitors given the 24-gamer is sure to gain external interest.

The Cats will have some wiggle room to please De Koning and his management come extension talks given they prepared hefty bids for trade targets Jacob Hopper and Brodie Grundy this off-season.

MELBOURNE, AUSTRALIA - MAY 14: Max King of the Saints and Sam De Koning of the Cats compete for a mark during the round nine AFL match between the St Kilda Saints and the Geelong Cats at Marvel Stadium on May 14, 2022 in Melbourne, Australia. (Photo by Quinn Rooney/Getty Images)

De Koning, one of the AFL's most exciting young key-position players, will be a key pillar in Geelong continuing their dominant run of September showings, with 2022 acquisitions Oliver Henry, Tanner Bruhn and Jack Bowes also set to aid their premiership retention.

De Koning's brother and Carlton tall Tom De Koning will also enter the final year of his contract with the Blues next year, with the Princes Park club facing a battle to retain a number of key personnel given their tight salary situation, however talks with the young ruck/forward are also underway at the Blues.

Cats small forward and All-Australian Tyson Stengle is also said to be in line for a new contract at Kardinia Park following his stellar first season with the Cats.

After seeing his AFL carer in jeopardy following Adelaide's decision to cut ties with him following a number of off-field indiscretions, Stengle found a lifeline with the Cats ahead of this year, where he played a significant role in their premiership run.

Stengle would play all 25 games for the Cats this year for a return of 53 goals.

Like De Koning, Stengle is off-contract next year, while other key Cats in Mark Blicavs, Bradley Close, Tom Hawkins and Zach Tuohy will also enter the final years of their respective deals in 2023.