The full-back ruptured ligaments and a scan has revealed the full extent of the damage.
"He has suffered a serious knee injury," said Franco Smith, the Glasgow head coach, in The Scotsman. "It will be an eight to 12-month injury. It's more serious than we hoped and it was confirmed on Wednesday night that he has ruptured ligaments in his knee. There was no contact, he was running and it just happened. Quite strange."