Turner set for Scotland debut
Italy and Scotland, who meet in Rome on Saturday in a Round Three encounter, have yet to register any points in this year's competition and are almost certainly contesting the wooden spoon.
Apart from Turner Scotland coach Vern Cotter called up Glasgow Warriors trio Grayson Hart (scrumhalf), Rob Harley (lock/flank) and Ryan Wilson (back row), along with Edinburgh back row forward Hamish Watson - who has two caps for his country.
The quintet replaces prop Alex Allan, back row Chris Fusaro (both head knocks) and hooker Pat MacArthur (thigh/groin) from Glasgow Warriors, and London Irish pair Blair Cowan (concussion) and Sean Maitland (thigh).
All of the players will continue their recovery with their respective clubs.
The Scotland squad has also been boosted by the availability of Harlequins wing Tim Visser and Glasgow Warriors centre Peter Horne - named in the original squad - who have completed their recovery from their respective hamstring and foot injuries to take full part in training this week.
Scotland:
Forwards: Ross Ford, Stuart McInally, George Turner (all Edinburgh), Alasdair Dickinson (Edinburgh), Zander Fagerson (Glasgow Warriors), Moray Low (Exeter Chiefs), Willem Nel (Edinburgh), Gordon Reid (Glasgow Warriors), Rory Sutherland (Edinburgh), Jonny Gray (Glasgow Warriors), Richie Gray (Castres), Tim Swinson (Glasgow Warriors), Ben Toolis (Edinburgh), John Barclay (Scarlets), David Denton (Bath), John Hardie (Edinburgh), Rob Harley, Josh Strauss, Ryan Wilson (Glasgow Warriors), Hamish Watson (Edinburgh).
Backs: Sam Hidalgo-Clyne (Edinburgh), Grayson Hart (Glasgow Warriors), Greig Laidlaw (Gloucester, captain), Finn Russell, Duncan Weir (both Glasgow Warriors), Mark Bennett, Peter Horne (Glasgow Warriors), Matt Scott (Edinburgh), Duncan Taylor (Saracens), Sean Lamont, Tommy Seymour (Glasgow Warriors), Tim Visser (Harlequins), Stuart Hogg (Glasgow Warriors), Ruaridh Jackson (Wasps).