Scotland fly-halves Finn Russell and Adam Hastings have been ruled out of the Autumn Nations Cup.
Russell limped out of the Six Nations win over Wales last weekend with a groin injury and will not be available for the games against Italy, France and Fiji this month.
Scotland head coach Gregor Townsend is optimistic the Racing 92 playmaker will be available for the 2021 Six Nations.
Hastings is expected to miss the tournament next year after doing damage to his shoulder following his introduction as a replacement for Russell at Parc y Scarlets
Townsend told BBC Scotland: "Finn we hope will be back in time for the Six Nations, but it's unlikely Adam will be back before the end of that tournament.
"At the very best he'll come back at the end, but that will depend on how things go."
Scotland face champions England in their first game of the Six Nations at Twickenham on February 6.