NARRM is facing a tough selection call between Ben Brown and Tom McDonald as the replacement for Harrison Petty in Friday night's top-four clash with Yartapuulti.

And premiership defender Christian Salem is on track to make his playing return this week after stringing together a mini pre-season over the past month.

Petty, a premiership-winning tall defender, has been ruled out for at least a month with a foot injury after impressing in his new role in attack this season.

He kicked two goals in Saturday's big win over Hawthorn before being substituted out at half-time.

The injury setback opens the door for regular forwards Brown and McDonald, who have played just three and four senior games respectively this season.

Narrm coach Simon Goodwin says Jake Melksham is another player in the selection mix to replace Petty.

Brown kicked nine goals in the opening three weeks before he was briefly sidelined by a back injury and lost his spot in the side.

McDonald has not played since a goalless, six-disposal effort in the round five loss to Essendon, which followed a four-goal haul against West Coast the previous week.

"He (Petty) is a really important player to us," Goodwin told reporters on Tuesday.

"We've been able to explore what it's like to have him in our forward half of the ground, and we've been really pleased with what that looks like.

"He does give us enormous flexibility as well - in games we can move him back at any stage.

"But it (his injury) presents opportunity for another forward to come in and play well, whether that's Ben Brown, Tom McDonald or Jake Melksham.

"We'll sit down once we get through training and look at what the options are."

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Young forward Jacob van Rooyen is likely to hold his spot in the side, with ruck duo Max Gawn and Brodie Grundy also presenting marking targets in attack.

While Petty has been sidelined, the Demons breathed a huge sigh of relief when scans cleared star midfielder Christian Petracca of serious ankle damage after the win over Hawthorn.

"It's a concern when you've got one of your players limping off the ground at the end of the game," Goodwin said.

"But he just got a rolled ankle late in the game in a tackle.

"He's ready to go. He'll train today, and he's feeling fully fit."

Salem was sidelined earlier this season with a recurring thyroid complaint, and his comeback plans in late April were halted by a knee injury.

The 27-year-old has now fully recovered, and will either line up in Friday night's top-four showdown with the Power, or in the VFL.

"He's had a month of full training. He's prepared for any level of footy," Goodwin said.

"We've been ultra-cautious with him in terms of his build-up. He's done a mini pre-season, so there's no doubt he's fully fit."