Scotland wing Sean Maitland will not link up with the squad ahead of their final round of the Six Nations game against France following a breach of Covid-19 protocols.
The 32-year-old was among the players who breached the bio-secure bubble while being part of the Barbarians squad last week ahead of the Quilter Cup game against England.
"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."
Meanwhile, Stuart Hogg, Jonny Gray and Sam Skinner, who were part of Exeter have been added to the squad along with Ratu Tagive, who is a cover to injured Damien Hoyland.
“Ratu was unlucky to have missed out a couple of weeks ago, picking up an injury on the weekend we selected our training squad," added Townsend.
“It’s great to have him with us now in addition to our three Exeter Chiefs – Jonny, Sam and Stuart.”
Scotland are positioned fourth in the Six Nations table with two wins and defeat apiece in four matches.