Wales international Rhys Webb will remain on the sidelines for a lengthy period following an ankle injury.
The Ospreys scrum-half sustained the injury during the clash against Australia at Millennium stadium last weekend and was released from the Wales squad for the remaining matches of the autumn internationals on Tuesday.
A statement released by the Welsh Rugby Union confirmed that the 27-year-old is suffering from a ligament tear which will need at least 12 weeks of recovery period, making him a doubtful starter for the Six Nations 2017 tournament.
Webb also missed out on the 2015 World Cup for Wales after sustaining a foot injury in the final warm-up game. He has been capped 23 times at the international level and has scored seven tries since making his debut in March 2012 against Italy.
Interim Wales coach Rob Howley has named scrum-half Gareth Davies as the replacement for Webb and he will start at nine on Saturday when they take on Argentina in their second game of the autumn internationals.
Following the Argentina clash, Wales will lock horns with Japan and South Africa in their remaining fixtures of November Tests.