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.
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.