Tom Ryder has been added to the Scotland squad for the opening two games of the Six Nations Championship.
The Glasgow Warriors lock has been called up after Fraser McKenzie injured his arm playing for Sale Sharks against Brive on Thursday evening.
Ryder, who qualifies for Scotland through his Glaswegian father, Paul, joined Warriors from Saracens on a two-month loan in August 2010.
The 26-year-old then made the move permanent and has made 35 appearances.
Ryder told the Warriors' website: "I'm delighted and proud to have received the call-up to the squad.
"First and foremost, my focus is on helping Glasgow Warriors win tomorrow's massive Heineken Cup match in Bath, but I'm really looking forward to joining up with the rest of the Scotland squad, putting in a lot of hard work and challenging for a place."
McKenzie will be seen by a specialist surgeon but has been ruled out of action in the immediate future.
Scotland head coach Andy Robinson said: "It's a blow for Fraser, but I've always stressed the importance of performing on Scotland A duty and consistently for your club.
"Tom has done this and deserves this chance."
Scotland squad for RBS 6 Nations Championship
Backs: J Ansbro (London Irish), M Blair (Edinburgh), C Cusiter (Glasgow Warriors), S Danielli (Ulster), N De Luca (Edinburgh), M Evans (Castres), S Hogg, R Jackson (both Glasgow Warriors), P Godman, L Jones, G Laidlaw (all Edinburgh), R Lamont (Glasgow Warriors), S Lamont (Scarlets), R Lawson (Gloucester), G Morrison (Glasgow Warriors), S Shingler (London Irish), D Parks (Cardiff Blues), D Weir (Glasgow Warriors). Forwards: J Barclay (Glasgow Warriors), K Brown (Saracens), G Cross, D Denton (both Edinburgh), A Dickinson (Sale Sharks), R Ford (Edinburgh), T Ryder, R Gray, D Hall (all Glasgow Warriors), J Hamilton (Gloucester), R Harley (Glasgow Warriors), A Jacobsen (Edinburgh), A Kellock (Glasgow Warriors), S Lawson (Gloucester), E Kalman (Glasgow Warriors), F McKenzie (Sale Sharks), E Murray (Newcastle Falcons), R Rennie (Edinburgh Rugby), A Strokosch (Gloucester), R Vernon (Sale Sharks).