Scotland number eight David Denton has been ruled out of his team's summer tour as he continues his recovery from concussion.
Denton sustained the injury while on duty for Edinburgh in the PRO12 a month ago, and was set to return to action in Scotland's Test against Argentina in Cordoba on Friday.
But the 24-year-old will miss the clash as well as Scotland's Test against South Africa in Port Elizabeth as he has not made a full recovery.
Scotland team doctor James Robson believes it's best not to risk the head injury.
"As we've always said we regard the welfare of our players as our principal priority and David has not recovered sufficiently to be considered for the intensity of Test match rugby against Argentina and South Africa," explained Robson.