Scotland captain John Barclay could be a doubt for the autumn Tests after the Scarlets confirmed on Tuesday he had undergone surgery on a ruptured Achilles tendon.
The Welsh side confirmed the extent of the back-row forward's injury after he was hurt during their Guinness PRO14 semi-final victory over Glasgow on Friday.
Barclay, who will join Edinburgh this summer following a five-year stint in Wales, will miss Saturday's final against Leinster in Dublin.
No timeframe has been put on the 31-year-old's recovery period, but six months is a normal rehabilitation spell for such an injury.
Scotland face Wales in Cardiff on November 3, followed by Murrayfield appointments with Fiji, South Africa and Argentina.
Barclay has won 71 caps and was an influential performer when Scotland claimed victories over Australia and England earlier this season.
It had previously been announced that he is among several senior Scotland players rested for the tour of Canada, United States and Argentina next month.
Scotland captain John Barclay holds the winner's trophy after the Six Nations match against France in Edinburgh in February 2018