Injury has also forced Rory Sutherland out of contention for Sunday's match at Murrayfield.
Uncapped flanker Darge - who was today named McCrea Financial Services Warrior of the Month for October - did not feature in Scotland's win over Tonga on Saturday while British and Irish Lions prop Sutherland was absent as Worcester beat Sale.
Edinburgh forward Magnus Bradbury, a late call-up to the squad last week, and winger Damien Hoyland, have also dropped out after not featuring against Tonga.
Three uncapped props - Northampton's Nick Auterac, Javan Sebastian of Scarlets and versatile Wasps forward Robin Hislop - have been added to the squad.
They had all been called up to Scotland's squad for the summer tour which saw all three games cancelled.
Glasgow lock Scott Cummings also comes in but is unavailable for selection following surgery on a hand injury last month.