WESTERN Bulldogs captain Bob Murphy has promised St Kilda counterpart Nick Riewoldt a hug at the opening bounce of Saturday night's 'Maddie's Vision' match - and then to order his team to "rip him apart".

The clash will raise money for research into bone marrow failure, the illness that claimed the life of Riewoldt's sister Maddie in February last year.

The opposing skippers gathered at Etihad Stadium on Wednesday and Murphy said the afterglow of the thrashing of Fremantle had quickly dissipated, with the Dogs particularly wary of a clash that also marks Riewoldt's 300th match.

"We go in with our eyes open on Saturday night that it'll go the distance," Murphy said.

"We clocked back into work on Monday, and (the teams) had two great hit-outs last year that went right down to the wire.

"Nick would appreciate this … I'll give him a hug before the first bounce and then I'll run into my pack and give them orders to rip him apart.

"I think that's the way it has to be."

The two young and exciting teams are building a strong modern day rivalry after the ledger was squared at one game apiece in 2015.

The Saints stunned the Dogs in round six by coming back from 55 points down to record a seven-point win, and then in an enthralling rematch in round 13, Luke Beveridge's men sneaked home by just six points.

Riewoldt was a constant thorn in Dogs' side in 2009 and 2010, with the Saints recording successive preliminary final wins over the boys from Whitten Oval.

Murphy revealed a strong friendship was forged from the disappointment.

"Nick's a special player and one of the great players of my generation," Murphy said. 

"He broke my heart a couple of times and like all great romances we patched it up. 

"I've respected him for a long time and more recently we've become good mates."

The respect for his foe-turned-friend has only been enhanced following Riewoldt's tireless efforts to raise awareness and funds for medical research.

Five dollars from each ticket sold for Saturday night's match will by donated to Maddie's Vision, the foundation established by Riewoldt and his family.

"I jumped at the chance to be involved in this, and I'm really proud to say, our footy club as well," Murphy said.  

"He has a special family as well, and it’s a cause so worthy."