MELBOURNE coach Paul Roos has slammed his players for their selfish attitudes, declaring it a key factor in Fremantle kicking away to a 68-point victory at the MCG on Sunday.

The Dockers led the Demons by 20 points at half-time and 30 points at the final change before powering away with the contest to boot seven goals to nil in the final term.

Roos said his players started to think about themselves, rather than the team.

"When things start to go awry, everyone gets into survival mode and it's about, 'How I can get in the best players?' and 'I'd rather kick the goal rather than let my mate kick it,'" Roos said in his post-match press conference.

"We still had chances in the last quarter but it became about 'I' rather than the team. They (Fremantle) played team footy for 120 minutes and that's why they're 5-0."

Roos even noted specific examples, in particular highlighting a passage of play where Dom Tyson ignored Mark Jamar for an easy handball in the final term and targeted the goals with a low-percentage snap instead.

The Demons' inaccuracy in front of goal also proved to be costly as they booted 10 behinds (six in the final quarter) and only one goal in the second half.

Roos said his side could ill afford to blow chances to hit the scoreboard against such a well-drilled lineup as top-of-the-table Fremantle.

"You've got to take your chances," Roos said.

"What you like to do is produce some really good football and make teams beat you, but I don't think we made them beat us.

"You can't miss goals and you can't turn the ball over against a good team."

Despite addressing some of the concerns with his team in a frank 10-minute meeting immediately after the game, Roos had significant praise for Jeff Garlett and young midfielder Angus Brayshaw.

"I thought Jeff Garlett's game was outstanding, given that he was competing against two or three opponents (a lot of the time)," Roos said.

"Brayshaw, his marking contest against Fyfe late in the game, he wins the contest which was terrific. So you're learning about guys from a positive sense and a negative sense as well."

Defender Christian Salem will be assessed during the week after he was substituted out of the game after half-time with concussion symptoms.

Salem copped a hefty knock right at the end of the second term when he was clipped across the head from an attempted spoil by Dockers forward Matt Taberner that earned him a 50m penalty.

Roos described Salem's head knock as "a delayed concussion", with Melbourne's doctors making the decision to sit him out for the rest of the game after his situation worsened after half time.

Salem was walking around in the Melbourne changing rooms after the match.