Reigning North Melbourne club champion Luke McDonald is facing another stint on the sidelines after lasting less than a quarter of his senior return during the Roos' fadeout loss to Adelaide.

McDonald left the field with an injured right pectoral after attempting a tackle late in the first term of the 41-point defeat against the Crows.

Teammate Cam Zurhaar will also miss North's round five clash with Geelong at GMHBA Stadium next Sunday after suffering concussion just moments after McDonald's injury.

Kangaroos coach David Noble said scans would determine how long McDonald would miss, having just returned after recovering from a pre-season quad complaint.

"Not sure about Luke's (injury), what the severity of it looks like. Pecs are never great from that side of things, so that's what it looks like it is. We probably won't know the severity of it until we get a scan," he said.

"They're a bit of an unusual one but they can sometimes be a bit nasty, so we'll just have to wait and see."

While disappointed with his team's final quarter fadeout, North Melbourne coach David Noble took plenty of positives away from the clash.

"The way we controlled the game for a lot of the portions … our fans and sponsors could walk away from the game with a vision of what we want to do," Noble said.

"Some of the young guys and the jobs we asked them to do and the manner they went about it was really good and we want to play the way we did today, each week."

Noble expected Josh Walker (hamstring soreness) to return for the clash with the Cats, and is hopeful of having experienced midfielder Trent Dumont play in the VFL on the same weekend.

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