North Melbourne forward Majak Daw is expected to be sidelined for up to six months because of a knee injury.
Daw will have surgery on a posterior cruciate ligament injury which he has managed during the season.
The 22-year-old has played six AFL games - the last of which was against Adelaide in Round 9 - and kicked six goals against the Western Bulldogs earlier this season.
The Kangaroos also have pressing injury concerns, with midfielder Jack Ziebell set to be given until the last minute to prove his fitness for Saturday's clash against Essendon at Etihad Stadium.
Ziebell suffered an ankle injury in North's loss to Adelaide and coach Brad Scott said the Kangaroos would make a late call on whether he plays.
"He'll have to do some more fitness testing. We'll stage that over the next 24 hours, right up until game time. He's a very important player for us," Scott said on Friday.
"He's critical to the way we want to play this weekend but he's also such an important player that we won't take any risks if there's any risk of long-term damage there.
"We're going to give him right up until game time. He's obviously named, we'll name him in the side and then make a decision as late as we can."
Scott is wary of the Bombers, who looked impressive early in the season but have struggled in the past three weeks.
He said James Hird's side were one of the best teams in the competition when at their best.
"I still think, at their best, they are a devastating football team. They get the ball in really dangerous positions and they move it forward at great efficiency," Scott said.
"Regardless of what's happened to them off the field, if they play that way on the weekend and we're not on our game and able to counter that, they're going to tear us apart.
"We're looking forward to Essendon's absolute best."