A FRUSTRATED Paul Roos says a section of Melbourne's team entered its clash with Essendon "big-headed" and took the Bombers lightly in their 13-point loss 

The Demons were expected to claim back-to-back wins for the first time since 2011 when they met the undermanned Bombers at the MCG on Saturday, but they slumped to a shock defeat in front of a crowd of more than 50,000. 

Melbourne trailed at every break and although it started the final term with consecutive goals and snatched the lead, the Bombers rammed on three late goals to take their first win of the year.

WATCH: Paul Roos' full media conference

Roos said a number of young Demons, including Jack Viney, Angus Brayshaw, Jesse Hogan and Clayton Oliver, looked tired throughout the day, but said there was another batch of players he thought probably underestimated the Dons.

"It's a bitterly disappointing day given our last month and where we think we're at, but hopefully it's not a true reflection of what we can dish up through the course of the year," Roos said post-match.

"We didn't see it going into the game… some of them would have gone into the game, possibly, thinking it's going to be an easy game. I think some of them were tired, so there's a distinct difference. But it's hard after the game to work out the 22 and put them in categories.

"I think there's some of them that probably would have turned up today thinking it's a pretty easy day at the office and we know in AFL footy it can certainly bite you in the backside."

The Demons were thrashed in all the key statistical areas of the game, falling to the Bombers in uncontested possessions (314 to 179), tackles (66 to 50), marks (139 to 68) and inside-50 entries (56 to 41).

Roos said the Dees' match committee needs to take some responsibility for the team that took the field, but said it was important to focus closely in the coming days on what went wrong.

"The guys you generally felt were tired, you have to work out whether you play them next week or rest them during the week. There's definitely that factor with probably half a dozen of them," he said.

Five talking points: Essendon v Melbourne

"The ones you perhaps thought were big-headed, you need to sit them down and say 'You've got to respect the competition'. There's a number of ways you go about it.

"Clearly from our point of view it's round two and we've had a good five weeks, but today was not acceptable. You've got to get back on the horse and work out ways to fix the problem."

The Demons take on North Melbourne next Sunday in Tasmania and Roos backed his team to bounce back, saying its horror performances have a random nature to them that doesn't necessarily correlate with previous weeks' form.

"We need to identify why the lack of consistency and why those games tend to happen," he said.

In his first match of the season Heritier Lumumba (18 disposals and four rebound-50s) won praise from Roos, while former Magpie Ben Kennedy (three goals from 21 disposals) also impressed.

Roos said the club would take lessons from the defeat.

"A team, whilst you want to play as a team, is made up of 22 individuals. Every individual needs to prepare himself well and present well every single week," he said.

"Today we didn't have enough individuals. So it does make me angry. It makes me angry for the supporters. But we've got to take responsibility as coaches as well, and clearly we didn't pick the right team."