Mundy has been one of Fremantle's best players this season, averaging 23 disposals a game to go with 17 goals.

The 292-game veteran is set to become just the second Docker to reach the 300-game mark, following 353-game stalwart Matthew Pavlich. (353 games).

Veteran goalsneak Hayden Ballantyne, ruckman Aaron Sandilands, and Bennell are also set to earn one-year contract extensions.

West Coast were sounding out the prospect of luring Sandilands their way in case restricted free agent Scott Lycett left the club at the end of the season.

But it's been reported that Sandilands has agreed to a new one-year deal at Fremantle that will see him combine coaching and playing duties.

Ballantyne's body has held up reasonably well this year, and Lyon is keen to have the 31-year-old stick around to help nurture a young forward line.

And injury-plagued Bennell will also be signed for 2019, despite playing just two AFL games in three years at the Dockers.

Bennell has managed 10 WAFL games this season in his most successful year at Fremantle to date, and he's set to return to playing duties for Peel Thunder this weekend after recovering from his latest calf niggle.

Lyon has been happy with Bennell's work ethic this year, but the former Sun can ill afford any serious injury setbacks next year.

"Going forward, going into that fourth year, we're all looking for some (return) in that investment, as is Harley," Lyon said.

"Next year would be a make-or-break year I would think."

Lee Spurr has already retired, while Michael Johnson and Danyle Pearce will also part ways at the end of the season.

Fremantle are in the middle of their four-year rebuild, and Lyon praised Mundy's influence.

"He leaves a really strong footprint here," Lyon said.

"He's really educating our young players, and modelling how to become a great player."

Fremantle also re-signed tagger Bailey Banfield, defender Taylin Duman, and forward Hugh Dixon earlier this week.

Lyon confirmed that skipper Nat Fyfe would return from a hamstring injury in Saturday's clash with Geelong at GMHBA Stadium.

Fyfe has missed six games with the injury, but has been given the green light by the club's medical staff.

Michael Walters is also set to play after scans showed the suspected hamstring injury he suffered against Carlton last week was actually a minor glute niggle.

But defender Luke Ryan will miss the rest of the season with a hamstring injury.

Australian Associated Press