Wales captain Alun Wyn Jones is out for six weeks with a shoulder injured suffered during Saturday’s Six Nations 20-18 defeat by France in Paris.
The 31-year-old lock was hurt hitting a ruck, and was replaced in the 51st minute by Luke Charteris.
Jones will miss club side Ospreys’ match with Stade Francais in a European Challenge Cup quarter-final on 2 April.
Jones has been tipped as a candidate to lead the British and Irish Lions on their tour of New Zealand this summer.
The WRU revealed the extend of the injury in a short statement.
“Alun Wyn suffered a shoulder injury in the France v Wales RBS Six Nations match at the weekend and, following scans and orthopaedic consultation, he will undergo an initial six week period of rehabilitation,” they said.
Jones captained the Lions in the final Test of their 2-1 series win over Australia in 2013.
Lions coach Warren Gatland names his squad for the New Zealand tour on 19 April and Jones is unlikely to feature before.
Can Ospreys plug the gap?
The Welsh region travel to Treviso in the Pro12 on Saturday, 25 March without their captain.
However, Lloyd Ashley is set to return from after overcoming concussion and Jones’ fellow Wales lock Bradley Davies is expected to return following a knee injury in April.
Backs coach Gruff Rees said: “Bradley’s just working through the final part of his procedures. I think mid-April might be a fair shout for us and he could really add to our squad.”
Ospreys can also call on uncapped Wales Six Nations squad member Rory Thornton at lock.
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