WHEN Aaron Sandilands walked in the doors at Fremantle in late 2001 he was already a giant of a man, but he will depart at season's end a giant of the football club after announcing his retirement. 

A four-time All Australian and dual Doig medallist, the former rookie will play his 271st career match and final home game in Saturday night's clash with Essendon.

One of the most dominant rucks in the game's history, Sandilands hangs up the size 18 boots as the all-time leader in hitouts (currently 8466) and among the most influential Dockers in the club's 25 years.

Only club legend Matthew Pavlich (353) and current teammate David Mundy (314) have pulled on the purple more times.

For a 211cm big man tipping the scales at 119kg, Sandilands showed remarkable durability across the majority of his career before injuries took a toll over the past four seasons.

The 36-year-old contemplated retirement earlier in 2019 after a pre-season calf niggle became a lingering complaint which threatened to keep him off the park for the entire campaign.

But Sandilands, famed his dedication and work ethic, made it back to face old foe Nic Naitanui in the round 16 Western Derby after more than 12 months out of the game and will fittingly farewell Dockers fans at Optus Stadium.

"I had a bit of a talk with family and friends (earlier in the year) and I was keen just to walk off into the sunset, to be honest," Sandilands said.

"(The farewell game) is probably not about me, it's about being able to say thank you to the people who have done so much along the way and have been able to help me out and to get me to where I am now.

"To be able to go out there on Saturday night and say one last thank you to all the fans, who have been riding the highs and lows along the way as well, it will be pretty special.

"It was getting frustrating doing basic skill drills and pulling the calf again, so there was a lot of doubt there that I'd ever get back and play again.

"But when you've got blokes like (club doctors) Ken Withers and Jeff Boyle who invest so much in the footy club and me personally, the conversations I had with them was 'why not have one more go?'.

"I'm so glad that those two guys talked me into try and go one more time."

Telling his teammates he was retiring and being unable to look close mate Hayden Ballantyne in the eye was tough, but Sandilands had no doubt in his mind.

Some had speculated he might play on next year, but pulling up sore from five games this season made the decision easy.

"The older you get the longer it takes to recover and to play at your best you've got to be able to train both main sessions in the week and I can't do that anymore," Sandilands said. 

"I've made the right call."

Sandilands made his debut in round one, 2003 in Wayne Carey's first game for Adelaide and established himself immediately, playing 19 games that year. 

His career coincided with another great ruckman from the west – Eagles games record holder and six-time All Australian Dean Cox – and the pair fought engrossing battles as the AFL's premier big men. 

Arguably the best year of his career came in 2010, when Sandilands polled a team-best 20 votes in the Brownlow Medal, and received his third-straight All Australian jacket.

But he was integral to Fremantle's most successful era under Ross Lyon between 2012-15 when Fremantle qualified for a maiden Grand Final and won the minor premiership.

Lyon built his side around Sandilands and big-bodied midfielders Nat Fyfe, Michael Barlow and Mundy, and his No.1 ruckman rarely let him down.

Sandilands amassed 44 hitouts in the 2013 Grand Final – more than double Hawthorn opponents David Hale (11) and Max Bailey (nine) combined – in a gut-wrenching 15-point defeat.

His lack of availability – playing just 31 games since the end of 2015 – made life tougher for the rebuilding Dockers, but Sandilands leaves the ruck division in strong shape after mentoring protege Sean Darcy and with Rory Lobb arriving via last year's NAB AFL Trade Period.

"It's safe to say that the AFL will never see another player like Aaron," ex-teammate and current football boss Peter Bell said.

"Aaron has the uncanny ability to make the difficult look easy, but no one worked harder than him to be at his fittest and strongest every game day.

"He is the model of what it means to be a Fremantle Docker. His work off the field to mentor our younger players has been second-to-none.

"He is often the first to put his hand up to host our first-year players when they arrive in WA, and he was a key off-field mentor for Next Generation Academy signing Jason Carter, who recently made his debut for the club.

"While we will no longer have Aaron helping win the ball our way beyond 2019, his contribution will be felt for many years to come." 

Aaron Sandilands career stats:

Pick No.33 in the 2002 Rookie Draft
All Australian 2008, '09, '10, '14
Doig Medal 2009, '15
Best clubman 2016, '18
Fremantle life member 2010