TABLE-TOPPING Melbourne faces a decision between recalling defender Harrison Petty or shifting Tom McDonald back to replace Adam Tomlinson for the remainder of the season.

Scans on Monday confirmed Tomlinson had ruptured his ACL in Sunday's win against North Melbourne in Hobart, sidelining him for the remainder of the year.

Tomlinson had formed a brilliant relationship with key pillars Steven May and Jake Lever in a three-tall defence this season, allowing Lever to zone off and play to his strengths as an interceptor.

Coach Simon Goodwin pointed to Petty or McDonald, who moved back against the Roos, as the options to fill Tomlinson's void when speaking after his side moved to 7-0.

"It's one of those areas we've been really strong in and he's (Tomlinson) done an incredible job to enable us to do the things we want to do with May and Lever," Goodwin said.

"Harrison Petty, who played a few weeks ago, is ready to play some really good AFL footy. That's exciting for us that he'll get an opportunity for us.

"Tom McDonald, as you saw today, we pushed him back and he performed really strongly. We've got a couple of options there that we'll look at as a coaching group, but we'll have to restructure a little bit behind the footy."

Petty has played one game this season (his 12th overall) in round five against Hawthorn when May missed due to concussion and a fractured eye socket.

May highlighted the 197cm defender's credentials when speaking to AFL.com.au in the pre-season.

"We've also got guys like Harry Petty who you probably haven't heard too much about, he's an up-and-coming gun," May said.

"He's that medium defender who can play tall or small, but he's super fit."

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Should the Demons opt to move McDonald back, it could open the door for key forward Sam Weideman to win a spot in attack.

The out-of-contract tall has played three VFL games for 14 goals but was overlooked at selection against the Roos in favour of Ben Brown who kicked majors goals on his AFL return.

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Meanwhile, the Demons will also be without star midfielder Jack Viney for 2-3 weeks after toe soreness forced him to be a late out for the clash against the Roos.

"Pleasingly there is no fracture and we have caught the hotspot in Jack’s toe extremely early," Demons football boss Alan Richardson said.

"Jack will be on a modified training program for the next couple of weeks and we are confident that this is a minor setback for him.

"We will monitor how Jack responds to the rehab plan with the aim for him to return in the next 2-3 weeks."