Hidalgo-Clyne joins Scotland after Pyrgos injury
Vern Cotter’s men defeated the Pumas 41-31 at a rain-lashed BT Murrayfield in the first Autumn International test.
Glasgow Warriors scrum-half Pyrgos suffered a concussive episode after coming on as a replacement, and will be subject to a graduated return-to-play protocol.
Scotland’s team doctor James Robson said: “The IRB head injury assessment trial proved its worth yesterday.
“It allowed us time to assess Henry fully and ensure he received the appropriate care.”
Other Scotland players were treated for injuries described by Dr Robson as ‘significant bumps and bruises’ but are not thought to be a cause for lasting concern.
Pyrgos had entered the fray in place of Greig Laidlaw in the 63rd minute.
Hidalgo-Clyne, 21, has represented Scotland at under-17, under-18 and under-20 level, as well as the 7s side, but is yet to make his full debut.
He can operate at half-back, fly half and fullback.