Rangers lose Bartley for six weeks
The on-loan Arsenal centre-back was forced out of last month's 2-0 win at Inverness Caledonian Thistle - his first match of his second spell with Rangers - with what has now been diagnosed as a hernia problem.
He also missed part of his first loan spell last season with a knee injury and is now facing the possibility of surgery.
Rangers director of football Gordon Smith told the Daily Record: "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. Either way, it's obviously a big blow for the boy and the club."