DEPARTING coach Paul Roos admits he was blindsided as Melbourne's young players fell into “the Grand Canyon" and sent him off with his biggest coaching defeat, a 111-point belting from Geelong on Saturday. 

Roos was left with a sour taste in his mouth following his 268th and final game in the box, after three years rebuilding the Demons into a likely finals contender in coming seasons.

The Dees were jumped from the outset by the hungry Cats and never gave a yelp, booting just six goals in a bitterly disappointing end to a promising 10-win campaign.

"It's just disappointing for the players after such a good season," Roos said post-match at Simonds Stadium.

"There weren't many signs during the week. I think I've mentioned the last two or three weeks we were always looking for little cracks that might be opening up in a group that's pretty young.

"Today cracks opened up and turned into the Grand Canyon and they all fell in a hole together.

"With credit to them (Geelong), they're a team playing for the premiership and playing premiership football, and when a young team drops off like that the result pretty much looks after itself as it did."

The Dees barely had a winner as the Cats ran riot at home, and Roos pointed out his side looked tired except for Christian Salem (27 disposals) and Angus Brayshaw (26, one goal) who have both spent time out with injury this year.

Roos bows out from his three-year salvage mission at Melbourne with 21 wins from 66 games in charge.

Despite the thrashing from Geelong, only the second 100-point defeat of Roos' coaching career, he was confident the Demons were still bound for success.

"I'd rather go out differently," the veteran coach said.

"I think it means something now as in the way I feel right here and now, but it's not going to make any difference round one next year and when the team's playing finals.

"Success will still happen, regardless of what happens today."

However, Roos – who led the Sydney Swans to the 2005 premiership – cautioned the Demons' young players that finals football wasn't guaranteed without them all accepting responsibility to get better.

"My advice to (Jesse) Hogan and all those young guys is you set your season up in the eight weeks when you're not here at the footy club," he said.

"We want growth from our young players, so the off-season is going to determine how Brayshaw, (Clayton) Oliver, Hogan, (Christian) Petracca, all those young guys, how their season goes next year.

"We know that we're not a finals team (yet), we've got a fair way to go to become a finals team and sometimes players need to see that because they don't necessarily believe it.

"I think today was a stark reality in exactly where we are as a footy club."