St Mirren have their fingers crossed that Darren McGregor has not suffered a second serious knee injury of his career.
The 27-year old defender, who returned from cruciate ligament damage a year ago, injured himself in the weekend's 2-1 loss to Hibernian and it is believed that he has again suffered a similar problem with manager Danny Lennon fearing the worst.
"Darren had a scan on his knee today (Monday) and we are now waiting on the full report," he told the club's official website.
"That being said we are 95% - although we await confirmation - that he has damaged his cruciate in the other knee from the one that was injured last season.
"It's a big blow for all concerned - for Darren, the club and the fans."