Scotland flanker Blair Cowan and winger Sean Maitland will both miss Saturday's Six Nations visit to Italy.
Cowan was concussed in the 27-23 defeat by Wales, while Maitland has a thigh injury that forced him to miss the match in Cardiff.
Alex Allan, Chris Fusaro and Pat MacArthur are also injury withdrawals from Vern Cotter's squad.
But winger Tim Visser and centre Peter Horne are in contention for selection after resuming full training this week.
Five new players have been called up to training - Glasgow Warriors scrum-half Grayson Hart and forwards Rob Harley and Ryan Wilson, along with the Edinburgh pair of uncapped hooker, George Turner, and back-row Hamish Watson.
Sean Lamont was a late replacement for Maitland in Cardiff, winning his 102nd cap.
Maitland's London Irish team-mate Cowan was a second-half replacement for John Barclay against Wales and in the opening loss to England.
Scotland's last Six Nations victory came in Rome, with Duncan Weir kicking a last-gasp drop-goal for a 21-20 success in 2014.
|Upcoming live TV coverage|
|Fri, 26 Feb (20:05 GMT)||Wales v France||BBC One|
|Sat, 27 Feb (14:25 GMT)||Italy v Scotland||ITV|
|Sat, 27 Feb (16:50 GMT)||England v Ireland||ITV|
|Six Nations coverage on the BBC|
Forwards: Ross Ford, Stuart McInally, George Turner, Alasdair Dickinson (all Edinburgh Rugby), Zander Fagerson (Glasgow Warriors), Moray Low (Exeter Chiefs), Willem Nel (Edinburgh Rugby), Gordon Reid (Glasgow Warriors), Rory Sutherland (Edinburgh Rugby) Jonny Gray (Glasgow Warriors), Richie Gray (Castres), Tim Swinson (Glasgow Warriors), Ben Toolis (Edinburgh Rugby). John Barclay (Scarlets), David Denton (Bath), John Hardie (Edinburgh Rugby), Rob Harley, Josh Strauss, Ryan Wilson (Glasgow Warriors), Hamish Watson (Edinburgh Rugby).
Backs: Sam Hidalgo-Clyne (Edinburgh Rugby), Grayson Hart (Glasgow Warriors), Greig Laidlaw (Gloucester), Finn Russell, Duncan Weir, Mark Bennett, Peter Horne (all Glasgow Warriors), Matt Scott (Edinburgh Rugby), Duncan Taylor (Saracens), Sean Lamont, Tommy Seymour (Glasgow Warriors), Tim Visser (Harlequins), Stuart Hogg (Glasgow Warriors), Ruaridh Jackson (Wasps).