Alun Wyn Jones's selection for the British and Irish Lions tour of New Zealand in June and July has been placed in doubt after the Wales captain was ruled out for six weeks with a shoulder injury on Wednesday.
"Following scans and orthopaedic consultation, he will undergo an initial six-week period of rehabilitation," the Welsh Rugby Union (RWU) said in a statement.
Jones, an experienced second-row, was injured in Wales's final Six Nations match against France last Saturday. He was replaced in the 51st minute as Wales lost 20-18 in Paris.
Warren Gatland names his Lions squad on April 19 and Jones is unlikely to feature for his Welsh club Ospreys before then.
The 31-year-old is considered as a potential captain for the tour after leading the Lions in their final test against Australia in 2013, which secured the series win. He also played on the 2009 tour of South Africa.
