Melbourne coach Paul Roos is now leaning more towards the stick than the carrot after Sunday’s AFL disaster.

West Coast’s 93-point demolition is Roos’ biggest losing margin as a senior AFL coach.

While the Demons are woefully undermanned in attack and were playing a much better side, Roos said he had to balance those factors against some shocking errors in the 18.15 (123) to 4.6 (30) mismatch.

The match was effectively over after the first 13 minutes, when the Eagles had kicked four goals to nothing.

Until now, Roos has been mindful about being careful with the psyche of a team that has suffered a lot in the last few years.

But as he said twice during his post-match media conference, his job is to make Melbourne better – whatever that takes.

“It’s round two, but I’m certainly putting together a dossier – my own dossier,” Roos said.

“It’s early in my tenure here, but you’re building up a profile on each of the players.

“You see them under the heat and you see what they can and can’t do.

“There are some non-negotiables in footy … if you can’t do them, you can’t play.

“At some point, you have to draw a line in the sand and say ‘these are the guys we’re going to pick’.”

Even though Roos had a fair idea of the task confronting him when he took on coaching Melbourne, Sunday’s horror show clearly rattled him.

His players dropped easy chest marks and turned the ball over at will.

“I haven’t seen that before, so it’s an eye opener for me as a new coach of the footy club,” he said.

“Some of the errors were incredible.”

While West Coast have opened the season with easy wins over the Demons and the Western Bulldogs, coach Adam Simpson also said there was plenty of room for improvement.

“We started pretty well and we lost our way a little bit there,” he said.

“Fortunately we kept the scoreboard ticking over.

“Overall, it was a frustrating game.”

Luke Shuey and Nic Naitanui starred for the Eagles, while Melbourne co-captain Nathan Jones was again outstanding.

Eagles defender Shannon Hurn was subbed off in the second term with a knee injury and Simpson said he would miss two to three weeks.