Eleven Warriors are in the Scotland squad to face Australia at Murrayfield and four more Glasgow players are on international duty across Europe.
The Barbarians take on Fiji at Ulster's Kingspan Stadium this evening with scrum half Nemia Kenatale starting on the bench for the Pacific Islanders.
Simone Favaro starts at openside for Italy as they face the All Blacks at the Stadio Olympico tomorrow afternoon.
At the Aviva Stadium in Dublin, Ireland host Canada with Djustice Sears-Duru starting in the front row for the away side and in Romania, Langilangi Haupeakui could make his second appearance for the USA Eagles off the bench.