De Boer will be playing his 100th AFL match for Fremantle in Saturday night's preliminary final at Subiaco's Patersons Stadium against the reigning premier Sydney with a grand final berth at stake.
Kirk played 241 games with the Swans, including the 2005 premiership, and this year has become an assistant coach under Ross Lyon at Fremantle. Lyon himself was also an assistant at the Swans as was Mark Stone so intelligence on Sydney is readily available.
Kirk only retired from the Swans at the end of 2010 and de Boer and the rest of the Fremantle players have been getting as much information on their Sydney opponents as possible leading into Saturday night's encounter.
"He obviously has some more intricate knowledge of them and has helped feed that through to the boys," de Boer said.
"Obviously the game plan has changed a little bit since he was there, but in terms of knowing the players a little bit it definitely has been helpful."
The Swans might be the walking wounded, without a host of stars and having to travel to Perth, but de Boer is far from expecting the Dockers to have an easy path in to the club's first ever grand final.
Fremantle will host the club's first ever preliminary final on Saturday night against the reigning premier Sydney who will be without Adam Goodes, Kurt Tippett, Sam Reid, Rhyce Shaw and Tom Mitchell.
The Dockers entered the AFL in 1995 and it took until 2003 to make the finals, and until 2006 to actually win one and make a preliminary final.
That was Fremantle's only ever preliminary final before this Saturday night and even though the Dockers are warm favourites following the week off after beating Geelong at Simonds Stadium, de Boer knows that the Swans are going to put up one almighty fight.
"Being favourites means nothing. They are the reigning premiers and people have written them off before at their peril. We will have to be hot on our game early and stick to our game plan to take them down," de Boer said.
"We love the purple army and they are very vocal, but in terms of the ground we know that Sydney like playing here and they are a very hard running side so it won't hold any fears for them."
De Boer has certainly the noticed around Fremantle, and all of Perth, that has been building for the Dockers heading into their first ever home preliminary final, but he's been trying to block it out as much as he can despite appreciating the support.
"It's great for our fans and supporters," he said.
"Everyone is getting on board and we are even converting a few of the Eagles supporters over as well so it's good for WA football, but we know that what they want the most is for us to prepare the same as we have been all year.
"Seeing them down at training was great, but we are 100 per cent focused on the job at hand."
De Boer is a little nervous heading into the preliminary final in what is his 100th AFL game since making his debut in 2009, but that achievement takes a back seat to the enormity of the game.
However, the 23-year-old has been able to turn himself into an important member of the Dockers with him now spending most of his time as a forward with his main task to put pressure on the opposition, tackle them and sneak some goals from time to time.
"It's memorable to reach 100 games and it's something I will be pretty proud of when it's all said and done, but we have bigger fish to fry right now and it's all about the team this week," De Boer said.
"I'm really excited and a healthy amount of nerves is fine. We know that throughout the whole year we've been working on our routine and preparation, so we have to just do all that right for another week."