Paul Roos has described Melbourne as a team that spends games waiting to be beaten, made up of players who may never erase the scars of Melbourne's lean years and will have to be moved on if the Demons are to progress.

After conceding the last six goals to lose by 23 points, a game Roos lambasted as being so devoid of skill he'd never seen its like, the Demons coach forecast a last month of the season that would decide whether a number of players were still at the club next year.

"It's hard to know (with) each individual why, but I think there's clearly some that might not be able to get over what's happened here in the past," Roos said. "So they're the determinations you've got to make over the next four weeks.

"I think we're a team that's waiting to get beaten to be honest. I don't think we play to win, we just look up at the scoreboard and we go, 'I'm not sure how we're in front because we're playing that poorly.'

"You get enough of the ball ... but if you can't handball five metres to a teammate it's impossible to move the ball. Whether that's the fear of winning, getting beaten around the head so often, it's hard to tell."

Asked if his players faced a career-defining last four rounds, Roos said: "When you're a club like we are, everyone knows that, that's not rocket science. You've got to improve your list and bring players in and look to get better."

Roos said it was "the sixth or seventh time" the Demons had been in front in the last quarter and lost in a season that has reaped just four wins, including twice each against Port Adelaide and the Western Bulldogs. "So there's got to be a reason behind it, it just doesn't come back to bad luck,'' he said. 

"There's a reason behind the skill error, the breakdown at the stoppage, the kick-in. Collectively, if you can't work it out, then you've gotta make changes, you keep rolling that over.

"It's certainly not an aberration what happened today. So I think in that case you have to go back to the mindset, and we were waiting to get beaten. Of course if you're waiting to get beaten, generally what happens is you get beaten."

Asked if the task of rebuilding the Demons was tougher than he'd anticipated, Roos – who has extended his contract to a third year that will see him coach the club until the end of 2016 – said there was a willingness to improve that was being drowned out by a lack of belief.

"I think that lack of belief that we can win or we're capable of winning is far, far greater than what I'd imagined it could possibly be," he said.

While Lions coach Justin Leppitsch was also scathing of the poor quality of a game he thought at three-quarter-time was the worst he'd ever seen, Roos described the skill level as "deplorable" and the mistakes as "extraordinary".

"I didn't see them lack adventure, they just couldn't kick the ball from one to the other and couldn't handball it," he said.

The coaches were also in concert in their dismay at how the spectacle was further eroded by the roof being open which led to players and umpires being affected by the sun throughout the afternoon.

"Nah, terrible," Leppitsch said, adding that "to a man" the coaches were of the belief the roof should be shut at all times. "I spoke to the umpires before the game, they hate it. It's very difficult to look through shade and light and try to make an accurate decision. They probably won't admit to that, but they told me privately they're not happy making those calls."

Roos said it was "bizarre", but incidental to Sunday's result.

"I don't understand why it's not closed, regardless of the weather,'' he said. "An indoor venue, you spend however many hundreds of millions of dollars on it, and you leave the roof open."