Glasgow Warriors pair Peter Horne and Tim Swinson have flown to Canada to join up with Scotland after being asked to provide back-up for Vern Cotter's battered squad.
Duncan Taylor (calf) and Jim Hamilton (ankle) were injured in Saturday's 24-6 win over USA in Houston, Texas, and will return home to continue their recovery with Saracens.
That has now given centre Horne and lock Swinson opportunities to impress the new head coach.
The duo were scheduled to join up with the group ahead of clashes with Argentina and South Africa later in the summer tour but have now flown out early.
Cotter said: "This is obviously disappointing news for both (Taylor and Hamilton), who were keen to impress in the short time they had on this tour.
"Everyone in the squad wishes them well and a quick recovery.
"It's now up to Peter and Tim to continue the hard work put in by Duncan and Jim, and take advantage of this opportunity, as we prepare for another Test match."
Scotland will play Canada at the BMO Field in Toronto this Saturday in the second of four summer Test matches.
The national team will then fly to Argentina to face the Pumas in Cordoba on June 20, followed by South Africa in Port Elizabeth on Saturday, June 28.