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ESSENDON'S No.1 ruckman Tom Bellchambers has turned his back on free agency by signing a two-year contract extension to stay at Tullamarine.

The injured big man, who knocked back a lucrative offer from Greater Western Sydney last time he fell out of contract, was set to become a restricted free agent at the end of the season.

But Bellchambers, 26, has shown faith in the Dons' direction by inking a new deal until at least the end of 2017.

"I'm really happy to have signed on for a further two seasons," he said.

"The group of guys we have at the club makes coming to work enjoyable, and the strong bond amongst the playing group made my decision very easy in the end.

"Personally, I've been frustrated missing the back half of the season through injury, and as a playing group we know we are a better team than what we've shown this season.

"There's no doubt it's been a difficult period for the players and the club, but I'm confident in the playing group and our ability to respond next season."

A stress fracture in his foot has sidelined Bellchambers since round 10, compounding the loss of Paddy Ryder to Port Adelaide, and the Bombers have improvised in the ruck since.

Undersized part-timer Shaun McKernan has battled admirably in seven matches, while fellow recruit Jonathan Giles has managed only three senior games as the Bombers have slumped to 15th on the ladder.

"Tom is obviously crucial to the team's structure, we know he's a fierce competitor, he brings a strong physical presence on game-day and he also provides us with another key target up forward," interim Bombers coach Matthew Egan said.

"Tommy has shown on numerous occasions he has the potential to be one of the most dominant ruckmen in the competition, he just needs some luck with injury in order to build some consistency in his game."

Bellchambers, whose 2014 campaign was ruined by an ankle reconstruction, has played 79 games since he was taken by the Bombers with pick eight in the 2008 pre-season draft.

Prior to re-signing, he was one of up to 20 Bombers believed to be in contract limbo following the departure of former coach James Hird.

Tall swingman Jake Carlisle looms as the main trade target for rival clubs, with North Melbourne coach Brad Scott throwing the Kangaroos' hat into the ring for the big man this week.

Paul Chapman has since announced his retirement and will play his final match against Richmond at the MCG on Saturday night, while the Bombers will weigh-up giving Dustin Fletcher (groin) a possible final appearance in round 23 against Collingwood.