Key defender Lachie Henderson has become the latest Carlton player to have his AFL season ended by injury.
The Blues backman will have surgery on Friday to fix a nagging groin injury which has caused him to be sidelined three times this season for several weeks at a time.
Carlton football manager Andrew McKay said it had become apparent that even if Henderson had a five or six-week spell, there was no guarantee the injury would heal naturally.
That has prompted Henderson to submit for an operation this week, rather than attempt another comeback later in the season, then possibly still need surgery later in the year, which could affect his preparation for next season.
"After speaking with the medical staff I decided it was best to have the surgery as soon as possible," Henderson said on the club's website.
"Having the surgery now will ensure I will be able to complete as much of the pre-season training as possible."
Henderson joins fellow defender Jeremy Laidler (knee) and ruckman-forward Shaun Hampson (knee) as players out for the year.
The Blues are also missing Jarrad Waite, Andrew Walker and Kade Simpson through injury and captain Chris Judd to suspension.
The injury list also includes Matthew Kreuzer (hip), Mitch Robinson (calf), Zach Tuohy (back) and Kane Lucas (hamstring), who will all need to prove their fitness if they are to return against Richmond at the MCG on Saturday night.
The Blues will regain ruckman Robert Warnock from suspension.