Gordon Bulloch, Andy Hall, Cammy Mather, Euan Murray, Jon Petrie, Graeme Beveridge, Andrew Henderson, Sean Lamont, Dan Parks, Sam Pinder and Graeme Morrison are all included.
A number of those will be attending on Tuesday only, while other players will be released back to their clubs on Wednesday in order for them to play in weekend fixtures.
Forwards
Ross Beattie (Gwent Dragons), Gordon Bulloch (Glasgow Warriors), Simon Cross (Edinburgh Rugby), Andrew Dall (Edinburgh Rugby), Bruce Douglas (The Borders), Ross Ford* (The Borders), Iain Fullarton (Sale Sharks), Scott Gray (Bath Rugby), Stuart Grimes (Newcastle Falcons), Andy Hall (Glasgow Warriors), Dougie Hall (Edinburgh Rugby), Nathan Hines (Edinburgh Rugby), Allister Hogg* (Edinburgh Rugby), Allan Jacobsen (Edinburgh Rugby), Alastair Kellock* (Edinburgh Rugby), Gavin Kerr (Leeds Tykes), Scott MacLeod (The Borders), Cameron Mather (Glasgow Warriors) Andrew Mower (Newcastle Falcons), Euan Murray (Glasgow Warriors), Scott Murray (Edinburgh Rugby), Jon Petrie (Glasgow Warriors), Robert Russell (Saracens), Craig Smith (Edinburgh Rugby), Tom Smith (Northampton Saints), Simon Taylor (Edinburgh Rugby), Jason White (Sale Sharks)
Backs
Graeme Beveridge (Glasgow Warriors), Mike Blair* (Edinburgh Rugby), Chris Cusiter* (The Borders), Simon Danielli (Bath Rugby), Matt Dey* (Edinburgh Rugby), Marcus Di Rollo (Edinburgh Rugby), Phil Godman* (Newcastle Falcons), Andrew Henderson (Glasgow Warriors), Ben Hinshelwood (Worcester), Sean Lamont (Glasgow Warriors), Brendan Laney (Edinburgh Rugby), Derrick Lee (Edinburgh Rugby), Gareth Morton (The Borders), Dan Parks (Glasgow Warriors), Chris Paterson (Edinburgh Rugby), Sam Pinder (Glasgow Warriors), Tom Philip* (Edinburgh Rugby), Gordon Ross (Leeds Tykes), Nikki Walker (The Borders), Simon Webster (Edinburgh Rugby), Graeme Morrison (Glasgow Warriors), Alistair Warnock* (Edinburgh Rugby)
* = Member of the Scottish Institute of Sport.