DALE Morris will extend his AFL career into a 13th season next year after signing a new one-year deal with the Western Bulldogs.

Morris, 33, has played on a year-to-year basis in recent seasons and AFL.com.au understands the defender and the Bulldogs recently agreed to terms for him to play on in 2017.

Morris was set to become a free agent at the end of this season, but his name was missing when the AFL released an updated list of 2016's group on Thursday afternoon.

Richmond forward/ruckman Tyrone Vickery, Fremantle pair Chris Mayne and Zac Clarke, Collingwood key defender Nathan Brown and twin brother and West Coast tall Mitch Brown are among the higher-profile names still eligible to become free agents in October.

Vickery's future has been the subject of much speculation amid the Tigers' disappointing season, while Mayne is widely tipped to be on his way out of Freo, with North Melbourne considered his most likely destination.

Clarke has also attracted interest from Victorian clubs and, given Fremantle is expected to be active this trade period, his future is unlikely to become clear until later in the year.

The Brown twins will be in demand in a market in which key defenders are highly sought after, with industry sources suggesting Mitch is the most likely of the pair to be at a new home in 2017.

A host of veterans remain on the free agency list including Luke Hodge, Kade Simpson, Adelaide's Scott Thompson, Dane Swan, Jimmy Bartel, Corey Enright and Sean Dempster.

Hawthorn coach Alastair Clarkson said in June he hoped Hodge, 32, played on next season, and the Hawks skipper is understood to want to continue, while Simpson, 32, has said he is in talks with Carlton about a new deal.

Enright, 34, and Dempster, 32, remain key members of their respective backlines at Geelong and St Kilda and appear well placed to play on if they wish, as does midfielder Thompson at Adelaide.

However, Swan's decision will be influenced by the progress of his rehabilitation from a badly broken leg and foot, and Bartel has triggered a contract extension for 2017 but is grappling with whether there will be a regular senior position for him at the Cats next season.

North Melbourne also faces some tough decisions on veterans Brent Harvey, Drew Petrie, Michael Firrito and Daniel Wells.

Wells seems almost certain to play on next season, but North could be reluctant to give the injury-prone star the two-year deal he is understood to want.

Of the other three Roos, AFL games record holder Harvey appears best placed to play on, with North's decisions on Petrie and Firrito complicated by the fact fellow veterans Jarrad Waite and Nick Dal Santo are also out of contract.

Morris played the Bulldogs' first 17 games this season before missing last Friday night's loss to Geelong with a minor hamstring injury.

The 2008 All Australian is a chance to return against North Melbourne on Saturday night and remains a key member of the Bulldogs' defence.

Remaining 2016 free agents - (R) denotes restricted free agent

Adelaide

Ricky Henderson

Scott Thompson

Nathan van Berlo

Brisbane Lions

Daniel Merrett

Carlton

Kade Simpson

Dennis Armfield

Collingwood

Jarryd Blair

Nathan Brown (R)

Brent Macaffer

Dane Swan

Alan Toovey

Essendon

Courtenay Dempsey

Brent Stanton

Tayte Pears

Fremantle

Zac Clarke

Matt de Boer

Chris Mayne

Clancee Pearce

Matthew Pavlich

Geelong

Jimmy Bartel

Corey Enright

Tom Lonergan

Hawthorn

Luke Hodge

Brendan Whitecross

Melbourne

Jack Grimes (R)

North Melbourne

Michael Firrito

Brent Harvey

Drew Petrie

Daniel Wells

Port Adelaide

Paul Stewart

Richmond

Tyrone Vickery (R)

St Kilda

Sean Dempster (R)

Sam Fisher

Sydney Swans

Ted Richards

West Coast

Mitch Brown

Sam Butler

Patrick McGinnity

Western Bulldogs

Matthew Boyd

Will Minson