Cath Riewoldt knows how big this week is. She has no doubt it's her husband's greatest achievement, and she doesn't mean playing 300 games of football.

"When you look at the platform these players have ... what he's been able to do, the awareness he's created," she says of Nick Riewoldt fronting Maddie's Vision in memory of his late sister. "Just his candidness, his wanting to do that rather than hide behind closed doors, which I know he wants to do at times. To do what he's done is just incredible."

For Riewoldt, Maddie is all that will be missing when St Kilda meet the Western Bulldogs on Saturday night. Yet her spirit will course through the occasion, and make it all the more special for the man at its heart.

"To be able to pay tribute to her, to honour her legacy and raise some money for bone marrow failure syndrome, it's a great thing to be able to do that while we celebrate my 300th," Riewoldt said, humbled by the focus yet grateful to be able to leverage off this rare football mark in a bid to help others.

Bulldogs captain Bob Murphy joined the Riewoldts, their toddler James and Nick's parents and brother at Etihad Stadium on Wednesday, amid the purple balloons, cakes and other "pop and colour" (Riewoldt's words) that drew attention to the cause.

After 16 seasons as arm's length opponents, Murphy and Riewoldt and their wives emerged from the off-season tour of Ireland as firm friends. The lyrical Bulldog is honoured to play a part in an event where $5 from every ticket will go to Maddie's Vision, at a venue where he and Riewoldt are one and two (160 Murphy, 158 Riewoldt) for games played.

"Special player, one of the great players of my generation," he said of the great Saint, who broke Murphy's heart in the 2009 and 2010 preliminary finals. "But, like all good romances, we've patched it up". Murphy looked forward to a hug at the coin toss, then ordering his pack to rip the milestone man apart. Riewoldt called the prospect "a bit awkward", but acknowledged the sentiment.

He met his future wife in Las Vegas as the 2009 Saints put the disappointment of grand final defeat behind them. She still sees him as "that crazy, annoying guy who wouldn't leave me alone"; it heartens her that, after Maddie died last February, people get to see a side of her husband that football tends to mask.

"They're obviously just people and Nick has exhibited that this past year, being so public and raw with his emotions and the grieving process. That's maybe why he's liked by so many people. They can see that real side of him and can relate to that."

They have been open about plans to spend an extended period in the US when his football is done. Cath likes the notion of James and any future children experiencing both cultures, but cautions Nick he'll miss "that surge of importance" that's inescapable in Melbourne.

He's not so sure, joking he has added motivation this season as the "poster boy" for senior players angling not to start pre-season training until after Christmas, after he spent the latter months of 2015 in Texas with Cath's family. He noted there was an element of necessity for him after "a particularly emotional year".

The prospect of a post-football life in a place that has neither knowledge nor care for AFL is appealing. "I've sort of experienced it to a micro-level in that I've been there in September, waking up and checking the phone to see who won the grand final. It's been strange, but sort of nice at the same time. It's refreshing."

For now, the honour of joining Barry Breen, Nathan Burke, Stewart Loewe and Robert Harvey as 300-game Saints is exciting enough. Riewoldt remembers being "devastated" to miss, because of injury, the time when Burke and Loewe shared the milestone in his first season, and being "insanely jealous" of fellow newbie Justin Koschitzke running out with them.

He loved the little gold 300 on their jumpers, and will have lasting recognition of his own on Saturday night, including "Rooey 300" caps for fans to doff in salutation. A video of Saints luminaries, former teammates, captains, Ross Lyon in his Fremantle office and other footy folk was aired on the scoreboard on Wednesday, setting a moving scene.

For years, Riewoldt has been an avid reader of the classics, but admitted medical grant applications and minutes from board meetings have consumed him of late. He read James Spot's First Easter the other day, and has Cath riding him to get back to big books. "Reading and yoga are the best medicines for him."

A full house sharing Maddie's Vision on Saturday night would be a rich tonic, too.

This article was written by Peter Hanlon from The Age and was legally licensed through the NewsCred publisher network.