Sean Maitland's season has come to a cruel end with the Saracens wing to miss out on the Aviva Premiership semifinals as well as Scotland's international series in the Southern Hemisphere next month.
The 28-year-old -- who represented the British & Irish Lions in 2013 -- has undergone surgery on his right ankle earlier this week and will be sidelined for three months.
Maitland sustained the injury in Saracens' defeat to Wasps in the final round of the Premiership.
Scotland face Italy, Australia and Fiji in June in what will be Gregor Townsend's first series in charge since the departure of Vern Cotter.
Townsend has drafted in Glasgow wing Rory Hughes and London Irish fullback Greig Tonks following Maitland's withdrawal.
"We've watched Greig [Tonks] closely this season. He's done really well in a good London Irish side and played a lot of full-back but also covered at centre and stand-off," Townsend said.
"He's a player that brings aggression and a really good kicking game but also has the ability to step up at first and second receiver. Primarily we're looking at him as a 15 but it's positive he can cover other positions as well.
"Rory [Hughes] has had a really good season. He was on excellent form before the injury he suffered just before Christmas and got back to that form towards the end of the season.
"This is an opportunity for him to continue the good work he put in this season, in particular leading up to the autumn Tests."