Johnnie Beattie is the latest tourist to suffer injury during Scotland's ill-fated trip to South Africa.
The 27-year-old forward is doubtful for Saturday's international against Italy in Pretoria after hurting his thigh in training.
Beattie sat out the final session on Friday and, if he fails to recover in time, then Rob Harley will start at flanker with David Denton moving to No 8.
Interim head coach Scott Johnson admitted: "We will see how Beattie pulls up in the morning.
"He is a tough lad and resilient and has played injured before.
"We'll make a late decision: One, because we have no choice and, two, because he has the character to carry it."
During the tour so far, Scotland has seen five of their players return home already.