The extent of the injury isn't yet know but it's understood that Cammy has had an x-ray. In his Sunday Herald column Cammy explains how the injury happened.
"For me it was a huge disappointment. I pulled down Danny Grewcock at a rolling maul and when I landed there was an almighty crack. I didn't want to be a hero and try to play on if it was going to weaken the team overall. I just didn't have any power in my leg and couldn't run, so I had to come off. I'm not sure just yet quite how serious the injury is."
You can read Cammy's Sunday Herald article here
You can read Gordon Bulloch's Scotland on Sunday article here