The four clubs that were reportedly in play for Carlton's Tom De Koning have been revealed, with two of those sides understood to have offered long-term contracts.

De Koning pledged his loyalty to the Blues last week in spite of significant rival interest, re-signing at Princes Park for a further two seasons. In doing so, he reportedly fended off overtures from four intrigued parties, the identities of whom have been shared.

During the most recent episode of the Tradies podcast, journalist Sam McClure revealed the four clubs understood to have either been interested in, or made an offer to De Koning, prior to the tall's Carlton recommittal.

The SydneySwans reportedly offered De Koning a whopping eight-year contract, while Geelong was said to have tabled a five-year deal to join brother, Sam, at Kardinia Park.

Meanwhile, Essendon and St Kilda also registered substantial interest in the ruck-forward, looking to bolster their key-position stocks amid rises up the ladder.

"Eight years [offered by] Sydney, eight years," stated McClure on Tradies.

"[De Koning was] offered five years at Geelong, interest also from Essendon and St Kilda.

"Essendon, St Kilda, Geelong made a five-year offer, Sydney made an eight-year offer, he stays at Carlton for a further two years.

"It's an incredible decision by Tom ... It shows incredible loyalty, I think the money from Sydney was pretty significant.

Fellow industry insider Mitch Cleary chimed in, posing the all-important query of what is next for those clubs that were supposedly turned down by De Koning.

"Now the spin-off comes off it ... So, now what happens next is, clubs that you spoke about; St Kilda, Sydney, Geelong and Essendon look to the market and think 'what's next?'" Cleary raised.

The Saints remain likely to target players of key-position status this year, following list boss Stephen Silvagni's earlier flagging of key stocks as a St Kilda area of need.

Meanwhile, the Swans have been heavily linked to West Coast's Tom Barrass and GWS' Harry Himmelberg, suggesting they're still keen on talls post-Lance Franklin and considering the concussion issues clouding the McCartin brothers.

The off-season exchange space is set to spice up in the coming months.