Sean Maitland has dropped out of the Scotland squad for the Six Nations visit to Wales after breaking Covid-19 rules when on Barbarians duty.
The experienced winger was part of a group of 12 to ignore protocols, which led to the cancellation of Sunday's game with England at Twickenham.
Fellow winger Damien Hoyland and lock Grant Gilchrist have picked up injuries and will miss all of the autumn Tests.
Uncapped Glasgow winger Ratu Tagive has been called up.
"Ratu was unlucky to have missed out a couple of weeks ago, picking up an injury on the weekend we selected our training squad," said head coach Gregor Townsend.
"We are working hard to ensure our training camp remains secure in terms of Covid protocols and as such Sean's actions last week with the Barbarians mean that he won't be able to rejoin our group now and we will review the situation in the coming weeks."
Number eight Matt Fagerson suffered an ankle injury in Friday's 48-7 win over Georgia and will not be considered for the trip to Llanelli.
Captain Stuart Hogg returns, along with Exeter team-mates Jonny Gray and Sam Skinner, following their success in the Premiership final on Saturday.
Following the conclusion of the delayed Six Nations, Scotland play Autumn Nations Cup matches against Italy, France and Fiji, with one more fixture on finals weekend.