Scott Murray was among four players called into Monday's training session after injuries struck Scotland's Six Nations preparations.
Montauban lock Murray has made 87 appearances for Scotland
Record cap holder Murray, left out of the original squad, joined up along with fellow forwards Craig Smith, Bruce Douglas and Dougie Hall.
Euan Murray (calf), Jim Hamilton (ankle), Dave Callam (shoulder/neck) and Kelly Brown (shoulder) withdrew.
Andrew Henderson, Simon Taylor and Rob Dewey are also carrying injuries.
"It's good to be back," Murray, who last featured in the World Cup defeat to New Zealand, told BBC Sport.
"I'm pretty excited and hopefully I can feature during the Six Nations.
"But there is still a long way to go and there are a lot of people playing really well at the moment."
Scotland kick off their campaign at home to France on 3 February, while England also visit Murrayfield.