Luckless Carlton defender Caleb Marchbank will miss up to eight weeks with a knee injury, while Adam Cerra has been ruled out for a fortnight.
Marchbank made his first AFL appearance in almost three years in last Friday's 26-point win over Essendon.
Despite playing out the match, a subsequent assessment of his knee revealed a lateral meniscus tear.
Marchbank underwent surgery on Tuesday afternoon and the 25-year-old is set to miss the next six to eight weeks.
It's a cruel blow for Marchbank, who has suffered a fractured vertebrae in his neck, a torn ACL and a persistent calf injury in recent years.
"Caleb is understandably really disappointed as we are as a footy club given how hard we all know Caleb has worked to get himself back and ready to play at the elite level," Carlton's head of football Brad Lloyd said.
"Caleb has had more than his fair share of bad luck which makes this news tough to hear.
"But as we all saw on Friday night he is more than capable of performing at the level and all we can do is support him through this period of his recovery."
Cerra suffered a low-grade hamstring injury in the win over Essendon and has been ruled out for two weeks.
Jacob Weitering (AC joint), Mitch McGovern (hamstring), Zac Williams (calf) and Marc Pittonet (knee) are other key players on the injury list.
The Blues (9-3) sit in fourth spot and take on Richmond at the MCG on Thursday night.
