Ireland captain Rory Best will miss Saturday's Six Nations clash with Italy through illness.
Hooker Best had been absent from their final training session ahead of the encounter in Rome, but was still expected to feature at the Stadio Olimpico.
But Muster's Niall Scannell will now start in the middle of the pack in his place. Leinster's James Tracy takes Scannell's place on the bench.
Best had made 51 consecutive Six Nations appearances for Ireland, who are looking to bounce back from last weekend's surprise 27-22 loss to Scotland.