Melbourne captain James McDonald said the playing group was in shock when told of club president Jim Stynes' cancer diagnosis at an emotional meeting on Thursday morning.

McDonald said the players had no inkling of what to expect when brought together to meet with Stynes less than an hour before the 43-year-old announced that he would be stepping aside to undergo treatment for cancer that had spread to several parts of his body.

"The good thing about Jimmy - I've known him for a long time and played with him in 97-98 - he's got great mental strength and he's really positive about life," said McDonald.

"He's not sitting round feeling sorry for himself, that's what I've taken from it - he's ready for another challenge."

McDonald said Stynes' cancer diagnosis had put the Demons' broader concerns into perspective, and he promised to support the president's aim to transform Melbourne from a good club into a great club.

"Every one of us needs to step up a little bit and take a bit of Jimmy with us," said McDonald.

Melbourne Football Club vice-president Don McLardy, who will take the reins in the short-term, said Stynes' mental toughness was 'legendary' and his best wishes were echoed by the wider football community including Collingwood coach, Mick Malthouse.

"I lost my father two years ago and my wife lost her brother several years ago and he had three young kids so we've all been in that position," said Malthouse.

"It is a dreadful disease ... but we hope that everything possible that can be done is done, and we'll support him if we possibly can and our thoughts are with him and his family."

"There's no easy fix and it's a tough time."

In a prepared statement, AFL chief executive Andrew Demetriou said the football industry was united in its wish to support Stynes.

"Jim is one of the most respected people in football and across the community and the best wishes of the AFL and all football supporters go out to him, his wife Sam and his family at this time," Demetriou said.

"The tireless job Jim has done in transforming the Melbourne Football Club and bringing together the club's supporter base has been incredible and I know football fans from across all clubs will pledge their support for him."

"We wish Jim a speedy recovery from his illness."