Following an MRI scan, Glasgow Warriors centre Richie Vernon has undergone shoulder surgery which will rule him out for an extended period.
The international could, however, return before the end of the season.
Meanwhile, it's been confirmed that Peter Horne (foot) and Rob Harley (thumb) are making good progress as they continue their rehab from injury.
Glasgow Warriors head coach Gregor Townsend said: "We're disappointed to lose Richie (Vernon) for the next few months.
"He failed to progress as expected, so in the end an operation was required, which will keep him out for most of the season. We wish him all the best with his recovery.
"Rob Harley has joined in with training over the last few days and Peter Horne is working hard to get back soon."