Assistant coach Steve Tandy delivered a gloomy prognosis on the pair as the squad stepped up preparations for Sunday’s match with Australia at BT Murrayfield.
The home-based players who beat Tonga last Saturday have been joined by the exiles but Sutherland is a notable absentee.
The loosehead prop had to pull out of Worcester Warriors’ match with Sale Sharks at the weekend due to an oblique muscle injury, more commonly known as a side strain.
Tandy thinks Sutherland and Darge will not only miss the Australia game but also the matches against South Africa and Japan later this month.
“It looks like that, yeah,” said the coach. “It’s pretty brutal because you always get injuries, but an injury to Suzz is an opportunity for someone else.”
Pierre Schoeman would appear to be in pole position to step up after making his Scotland debut in the win over Tonga last Saturday but Jamie Bhatti will also come into contention.
Uncapped Glasgow flanker Darge is still suffering from an ankle injury he sustained against Leinster.
Scotland have called looseheads Nick Auterac (Northampton) and Robin Hislop (Wasps) into the squad along with tighthead Javan Sebastian (Scarlets). All three are uncapped.
Edinburgh pair Magnus Bradbury and Damien Hoyland have been released from the squad.