MELBOURNE veteran Daniel Cross is expected to miss up to six weeks with a broken leg.

In further disappointing news on the injury front, experienced forward Shannon Byrnes could also be ruled out for the rest of the season with a lingering foot problem.

Cross, who has been a key part of the Demons' revamped midfield this season, sustained the injury late in the club's match against North Melbourne on Sunday.

Amazingly, he played through the injury and complained he was sore after the game. The Demons sent him for an x-ray, but he was given the all clear.

The extent of the injury was only revealed after a scan revealed a small crack in his leg.  

Demons coach Paul Roos said the former Bulldog would spend a minimum of a month on the sidelines.

"It's a small fracture in one of the bones in the leg so it's a 4-6 week injury," Roos said at AAMI Park on Tuesday.

"That's not ideal for Crossy, he's been a really good player for us and pretty important.

"Hopefully he gets back in the shorter time frame, but he'll certainly be out for a minimum of four."

Roos said it was disappointing news for Byrnes.

"Unfortunately Byrnesy's hurt his foot again so he looks like being out for the rest of the season. We're just getting confirmation on that which is not too flash," Roos said.

The injury to Cross and the one-week suspension to Jordie McKenzie will force the Demons into at least two changes against the Western Bulldogs on Sunday.

The club accepted the one-game ban handed to McKenzie on Tuesday and Roos said the incident was out of character for the Demons' stopper.

"I always get disappointed. Particularly for a guy like Jordie who worked his way back through the seconds, I'm disappointed for him," he said.

"Sometimes you scratch your head ... I often say 'Why do it?' It's unnecessary and it just costs him and it costs the team.

"We're seeing coaches get more and more frustrated by those little incidents."

Dean Terlich, who was the emergency for the game against the Kangaroos, is likely to come into the selection frame for Sunday's game.

Viv Michie, Sam Blease and Jimmy Toumpas will also be talked about by the match committee.

However, Roos was dissatisfied with the performance of the Demons' VFL affiliate, the Casey Scorpions, which lost to the Box Hill Hawks by 85 points.

"Without individualising, I was really disappointed with our seconds," he said.

"[Box Hill's] young players came to play and that was what really struck me when I watched the game last night."

"They were fantastic and we were poor."