Wales scrum-half Tomos Williams faces up to four months on the sidelines after damaging his shoulder and looks set to miss the upcoming international programme.
The 25-year-old suffered the injury during Cardiff Blues' Pro14 defeat by the Scarlets on Saturday and will now undergo surgery.
The Blues said on their website that Williams, capped 20 times by Wales, would be out for an "estimated three to four months".
Wales are due to face Scotland on October 31 in their remaining 2020 Six Nations fixture. The game was postponed in March because of the coronavirus pandemic.
Wayne Pivac's side are then set to feature in a yet-to-be-confirmed eight-nation tournament.