North Melbourne star Shaun Higgins will spend up to six weeks on the sidelines after having surgery on his injured shoulder.
Higgins, the club's best and fairest winner for the past two years, injured his right AC joint when he landed awkwardly in a tackle during Saturday's win over Gold Coast.
"He'll have surgery this afternoon and will be targeting a round 17 or 18 comeback at this stage," North football boss Cameron Joyce said on Tuesday.
"Higgins' absence will hurt us, but it also provides an opportunity for one of our younger mids to step up.
"We have the likes of Paul Ahern playing great football in the VFL, as well as Bailey Scott, Kyron Hayden, Taylor Garner and Curtis Taylor."
Having won their first two games under caretaker coach Rhyce Shaw, the Kangaroos will host third-placed GWS on Sunday.
Defender Jamie Macmillan (calf) will undergo a fitness test but Sam Wright (ankle) and Dom Tyson (calf) both remain at least a week away.
The Giants expect star forward Toby Greene to play this weekend, having been a late withdrawal in round 12 because of a knee injury, but defender Nick Haynes will be an enforced omission.
Intercept specialist Haynes suffered an ankle injury during GWS's loss to Adelaide.
"We think he'll miss this week and probably next week," GWS football manager Wayne Campbell said.
"He was very brave to play on like he did ... scans revealed a grade one tear of an ankle ligament."