Pat MacArthur could make his Scotland debut against Italy on Saturday after replacing Dougie Hall on the bench for the clash.
MacArthur's Glasgow team-mate Hall was originally named as a replacement for the RBS Six Nations clash at Murrayfield but has been ruled out due to a knee injury.
Hall's problem has led to 25-year-old hooker MacArthur being called up to Scotland's match-day squad for the first time.
"Dougie has a mild strain of his knee which will not settle in time for this weekend's game," Scotland team doctor James Robson said:
MacArthur added: "It's a huge honour to have the chance to play for my country. It's something I've dreamed about since I started playing mini rugby at Ayr and aimed for since I became a professional with Glasgow Warriors."