London (AFP) - Leigh Halfpenny has been ruled out of Wales' Six Nations opener against Ireland on Saturday due to a back spasm.
The full-back was due to win his 98th cap in his first start for 19 months in the opening game of Warren Gatland's second spell in charge.
Halfpenny had overcome a serious knee injury to get himself back into contention for selection.
His replacement for the clash against the top-ranked side in the world at the Principality Stadium will be Cardiff's Liam Williams.
"Unfortunately, Leigh had a back spasm this morning and Liam will be playing," said Wales assistant coach Jonathan Humphreys."I think it's more disappointing for him as a person.He is an unbelievable professional and an unbelievable person.
"He has got to pick himself up again.You feel for him that he's got to pull out at this late stage."