His absence from a 26-man squad named yesterday was the main blow to the Scots as they seek to erase the memory of a drubbing at the hands of Australia nine days ago.
The former captain, Rob Wainwright, looks set to replace the unfortunate Adam Roxburgh - concussed against the Wallabies - after playing his first game in a month for his club, Dundee HSFP, at Glasgow Hawks on Saturday.
But doubts remain over two more Lions, Alan Tait and Gregor Townsend, with the Newcastle centre Tait given only a 50-50 chance of recovering from a hamstring pull sustained during training last week.
Townsend was reported as being "very positive" about overcoming a knee injury incurred during the same intensive session at Murrayfield.
SCOTLAND SQUAD (v South Africa, Murrayfield, Saturday): Backs: G Armstrong (Newcastle Falcons), C Chalmers (Melrose and Scottish Borders), J Craig (West of Scotland and Glasgow), D Hodge (Watsonians and Edinburgh), C Joiner (Leicester), K Logan (Wasps), A Nicol (Bath), R Shepherd (Melrose and Caledonia), A Stanger (Hawick and Scottish Borders), D Stark (Glasgow Hawks and Glasgow), A Tait (Newcastle Falcons), G Townsend (Northampton). Forwards: G Bullock (West of Scotland and Glasgow), S Campbell (Dundee HSFP and Caledonia), G Graham (Newcastle Falcons), S Grimes (Watsonians and Caledonia), D Hilton (Bath), S Murray (Bedford), G McKelvey (Watsonians), E Peters (Bath), S Reid (Boroughmuir and Edinburgh), I Smith (Moseley), B Stewart (Edinburgh Academicals and Edinburgh), M Stewart (Northampton), R Wainwright (Dundee HSFP and Caledonia), P Walton (Newcastle Falcons).