Scotland have called up Stuart McInally and Alex Dunbar to their summer tour squad after John Barclay suffered a hand injury and with Max Evans still absent.
Barclay is expected to make the first Test against Australia on June 5, but Evans is playing for Castres in the Top 14 semi-finals this weekend and does not need to be released under IRB regulations until the following weekend.
Scotland head coach Andy Robinson said: "We've called up Stuart as a precaution given a hand injury that John Barclay sustained in training."
He added: "John should be available for selection for the Test, but we felt it better to ensure we have sufficient back-row options.
"Alex will meet up with the squad [on Friday]. We've gone for him as we are still liaising with the IRB, French Federation and Castres to have Max Evans join us as soon as possible."
McInally, the 21-year-old Edinburgh back-row forward, will will join the tourists in time for their arrival in Newcastle, New South Wales on Saturday, the venue for their sole meeting with the Wallabies.
Dunbar, the 22-year-old Glasgow centre, will join up with the party in Sydney on Friday from Tasmania, where he has been visiting family.
Scotland also face Fiji and Samoa in the three-match tour.