Tim Visser faces sitting out Scotland's first three Six Nations fixtures after suffering an injury on duty with club side Harlequins.
The 28-year-old wing limped off with a hamstring strain during Quins' Premiership draw with Gloucester last weekend.
The former Edinburgh back now faces six to eight weeks on the sidelines.
The best case scenario would see him sit out of Scotland's opening Six Nations clash with England on 6 February at Murrayfield and Wales' visit to Edinburgh a week later.
But he could also miss the Dark Blues' trip to Italy on 26 February if his recovery fails to go smoothly.
Dutch-born Visser has played in 23 Tests, and made two appearances at this year's Rugby World Cup.
His injury comes just a week after head coach Vern Cotter lost the services of Glasgow lock Rob Harley to a thumb injury.
Ireland host Scotland on the last day of fixtures at 5pm on 19 March.
