The 32-year-old renowned tagger informed teammates of his decision on Thursday morning after being in and out of the GWS side for the bulk of season 2022 due to injury, with the veteran having been on the sidelines since Round 13 due to a concussion.
Starting his career at Fremantle in 2009 after being drafted at Pick 19, de Boer was at the heart of the Dockers side that made it to a maiden Grand Final in 2013, before being delisted in 2016 and subsequently picked up by Leon Cameron's Giants outfit in that year's national draft.
De Boer was quick to thank both clubs for the tutelage and belief they invested in him over the course of his 223-game career.
“I’d particularly like to thank Leon Cameron for believing in me and challenging me always to be the best version of myself.
“I’d also like to thank the Fremantle Dockers for first recruiting me and, in particular, Mark Harvey and Ross Lyon for teaching me the abnormal effort and football IQ required to perform at the highest level.”
GWS General Manager of Football Jason McCartney heaped praise upon the veteran, citing his best qualities as he reflected on a successful career.
“Matt is the ultimate clubman and epitomises everything you want in a leader,” McCartney said to the club's website.
“Most AFL players never reach 200 AFL games and Matt’s career is a testament to his hard work, sacrifice and relentless pursuit of excellence.
“Drafted as a rookie, delisted and starting again in Sydney – Matt could have easily given up at any point but his determination and drive to make himself, and others, better is unquestionable.
Although being delisted by the Dockers, de Boer burnt brightly during his time at Subiaco finishing runner-up in the club's best-and-fairest in both 2010 and 2011 before playing every game in season 2013 to help his side to the final Saturday in September.
His switch to Western Sydney saw him play in a preliminary final in 2017 before 2019 saw him come up short once again in the big dance, with the Giants going down to Richmond in a humiliating 89-point thrashing.
From that point on, de Boer's presence in the GWS best-22 dwindled despite being a leader at the club, only managing 36 games in his final three seasons with injury marring his run at a decent string of fixtures.
There is no doubt however that de Boer's presence will be sorely missed in the change rooms, with the club now undergoing what might be the most transition its faced in its relatively short history.
Interim coach Mark McVeigh will have a battle on his hands to keep as many of his players as possible over the off-season with the likes of Tim Taranto, Jacob Hopper, Tanner Bruhn and Bobby Hill amongst others either unclear on their future at the club or set to request a move elsewhere.
Whatever happens, there is sure to be a heap of shuffling around in Sydney's west over the summer.