Gordon Reid, the 26-year-old Glasgow Warriors prop, has become the third additional player to join the Scotland tour to South Africa.
Reid was summoned from his club's pre-season training to provide front-row cover as Euan Murray continues to be affected by a hamstring injury ahead of Saturday's Test against South Africa in the Mbombela Stadium in Nelspruit.
A product of the Ayr club, Reid was an unused replacement on the Scotland bench for the Test against Tonga in Aberdeen last November. He made his Scotland A debut in February's victory over England Saxons in Newcastle.
He follows his Warriors club-mates, fellow front-row forwards Jon Welsh and Fraser Brown as a call-up, Scotland having seen Ryan Grant receive an emergency summons to the Lions tour and lost Pat MacArthur and Geoff Cross to injury, the same fate befalling captain and back-row forward Kelly Brown.
"Given the injury situation we've faced we thought it prudent to call on Gordon as cover. Euan is working with our medical team to return to action as swiftly as possible," said Scotland manager Gavin Scott.
"Both Gordon and Fraser Brown arrived at our hotel this afternoon and will train with the squad tomorrow."
"It's really good to be called up to the summer tour. I was halfway through a training session with Glasgow when I got the call. I was really surprised but I'm determined to make the most of this chance," said Reid.