The big centre limped off in last weekend's 14-7 defeat in Galway, and head coach Gregor Townsend said: “Alex is improving. He had a scan and we’re waiting to get more details.
“The positives are that the ACL (anterior cruciate ligament, which kept Alex out for seven months last year) is not affected, but he is moving better. We won’t be able to make a call yet, but we should know at the beginning of next week if he is available or not."
Glasgow prop Sila Puafisi was red-carded in Galway with a hearing scheduled for early next week.
Gregor added: “We believe [the hearing] will be on Monday. So, with Alex as well, we should know going into Tuesday who will be available. Henry Pyrgos has trained twice this week and seems much more positive about his neck injury. We expect him to be available.”