Scotland's front-row trouble has led to Newcastle Falcons prop Grant Shiells joining the squad training camp ahead of the autumn Test with New Zealand.
Three of the four props named in head coach Andy Robinson's 34-man pool last week are carrying injuries.
Ryan Grant suffered a head knock in Glasgow Warriors' victory at Treviso on Saturday evening.
And Edinburgh duo Allan Jacobsen (hamstring) and Geoff Cross (concussion) are returning to fitness.
The 23-year-old Shiells, born in Melrose, has represented Scotland at Under-19 and Under-20 level and joined Newcastle in 2009.
Robinson said: "We've invited Grant to train with us given some of the recent injuries we've had on both sides of the front row."
But it is anticipated Jacobsen, Cross and Grant will be fit for the 11 November clash with the All Blacks at Murrayfield.
Cross is the only specialist tight-head in the squad, while four props are normally required on a match-day, with two named among the replacements.
Kyle Traynor, who left Edinburgh for Bristol in the summer and won three caps as a replacement in 2009, is the other prop in Robinson's squad.
There are a number of other injury concerns, with limited training at the St Andrews camp for locks Jim Hamilton (ribs), Al Kellock (back) and Richie Gray (ankle), flanker Ross Rennie (shoulder), stand-offs Ruaridh Jackson (shoulder) and Greig Laidlaw (neck), centre Nick De Luca (ankle) and wing/centre Sean Lamont (facial).