Rangers loanee Kyle Bartley will miss about six weeks with what was initially thought to be a groin injury.
The Arsenal defender is on a season-long loan at Ibrox but broke down in the win over Inverness Caledonian Thistle last month and the club has now diagnosed it is a hernia and he will have to be sidelined until mid-October.
"Kyle has a hernia problem and we expect him to be out of action for between five and six weeks, although I'm not sure at this stage if surgery will be required," director of football Gordon Smith said in the Daily Record.
"Either way, it's obviously a big blow for the boy and the club."
