Scotland head coach Vern Cotter has added Edinburgh duo Dougie Fife and Ben Toolis to his pre-World Cup training squad.
The Gunners pair have been called in to replace Glasgow Warriors lock Tim Swinson and Saracens centre Duncan Taylor, whose availability for the tournament being staged in England is now in doubt following injuries.
Swinson has ankle trouble while Taylor has been hit by a shoulder complaint and both men now require surgery.
They are both expected to be unavailable for up to three months, ruling them out of the Dark Blues' four warm-up games ahead of Scotland's opening Pool B match with Japan on September 23.
Winger Fife, 24, has scored 16 tries in 64 games for his club.
He earned three of his six Scotland caps in this year's RBS 6 Nations, scoring the only try in the team's 15-8 loss to France in Paris.
Meanwhile, 23-year-old lock Toolis earned his first cap as a replacement in the same campaign after a breakthrough season for the capital club, starting 20 of Edinburgh's 22 matches and scoring his first try in the side's European Challenge Cup semi-final win over Newport Gwent Dragons.