Glasgow Warriors hooker Brown joined the group in non-contact training last last week and is expected to take full part from today, with fellow Warrior and hooker Grant Stewart returning to the club.

Prop McCallum (22) last featured for Scotland on the 2018 summer tour and joins as fellow Edinburgh tightead Willem Nel continues his recovery from a calf strain sustained in the national team’s opening victory over Italy at BT Murrayfield Stadium on Saturday.

Exeter Chiefs forward Sam Skinner injured his ankle early in the first-half of the same game and has returned to his club for further assessment.