Ruaridh Jackson, Tom Ryder and Alex Dunbar could feature when Gregor Townsend names his team on Thursday.
Bath's stand-off Tom Heathcote has been drafted into the Scotland squad preparing for Saturday's game with Tonga.
The 20-year-old has already represented England at U20 level, and played for England in the IRB Junior World Championship this summer, but he was born in Inverness.