THE REMAINDER of Luke Dunstan's season is in doubt after the St Kilda midfielder tore his pectoral muscle in a scratch match against Richmond's reserves on Saturday.
The 25-year-old will head for surgery after scans confirmed significant damage.
He is expected to miss the next 10-12 weeks.
"Unfortunately, Luke will require surgery to repair the tear and will likely miss a large proportion of the season," Saints head of football David Rath said.
"Despite not being part of the AFL side on Saturday, Luke is an important part of our midfield group and it’s a blow to lose him for an extended period."
Dunstan had 21 disposals in the round one loss to North Melbourne but failed to retain his spot after the season restart from round two.
Zak Jones is unlikely to face Carlton on Thursday night given the five-day turnaround, but scans showed no major damage to his tight hamstring.
"Thankfully it isn’t anything major with Zak and we will wait to see how it settles this week before deciding on his selection against Carlton," Rath said.
Paddy Ryder is expected to be fit for selection after he was a late out against the Tigers due to soreness on Saturday.
Jarryn Geary is touch and go to return after a fortnight out with a hamstring strain, while Jimmy Webster is also expected to put his hand up for selection after he was managed out of last week's reserves scratch match.