Wales lock Alun Wyn Jones looks likely to miss the start of the RBS 6 Nations Championship after being ruled out for up to 16 weeks with a shoulder injury.
Jones, 27, suffered the injury towards the end of the first half of Wales' disappointing defeat to Argentina last Saturday and was subsequently ruled out of the remainder of the autumn series.
Scans on the injury have revealed the Ospreys skipper needs to undergo surgery to reconstruct his AC joint ligaments, and he will go under the knife later this week before facing a lengthy recovery.
Ospreys physio Chris Towers said: "He is due to undergo the surgery at the end of this week, and we will be looking at a 12-16 week rehab process post-op to get him back on the field."
The injury is a significant blow to the Ospreys as Jones will definitely miss the remainder of their testing Heineken Cup Pool Two campaign, with crucial games against Toulouse (twice), Leicester and Treviso still to come.
It is also doubtful Jones will be fit for the start of the Six Nations.
A 16-week absence would see the Lions second row miss the first three games of Wales' campaign against Ireland, France and Italy.