Wales' Dan Lydiate is anticipated to be sidelined for 12 to 14 weeks as he prepares for shoulder surgery.
Lydiate was ruled out of his country's tour of New Zealand last weekend after the Ospreys flanker injured his right shoulder against England at Twickenham in a match he started as captain with Sam Warburton absent.
Ospreys issued an update on the 28-year-old's condition on Friday.
Senior physiotherapist Anthony Carter said: "Dan sustained a significant injury to the AC joint in his right shoulder, caused by an impact during the England game on Sunday.
"He has been seen by Richard Evans, shoulder specialist at Spire Cardiff, who confirmed that the shoulder requires stabilisation via surgery, after which there is an expected rehab period of 12 to 14 weeks."
Lydiate has earned 57 caps for Wales and three for the British and Irish Lions since making his international debut in 2009.