Edinburgh duo Dougie Fife and Ben Toolis have been added to Scotland's extended World Cup training squad.
They are called up in place of Glasgow Warriors lock Tim Swinson and Saracens centre Duncan Taylor.
Both departing players require surgery for ankle and shoulder complaints, respectively.
Swinson and Taylor will be sidelined for up to three months and are expected to miss the four warm-up Tests ahead of the tournament kick-off in September.
Fife, 24, has been capped six times and scored Scotland's try in this year's 15-8 loss to France in the Six Nations.
Australia-born Toolis, 23, has made one international appearance as a replacement against Italy in the same disappointing campaign.
Head coach Vern Cotter selected 46 players for the training squad earlier this month and must cut that down to 31 by the end of August.