Kearney has been switched from his position on the left wing and as a result Leinster teammate Shane Horgan has been drafted into the starting line-up for the battle at Croke Park.
Girvan Dempsey has also failed a fitness test and will play no part in the battle to decide the destination of the 2008 Triple Crown.
With Wales just one win away from wrestling the Triple Crown from two-time defending champions Ireland, the loss of experienced Murphy is a boost to Warren Gatland’s side.
Kearney will now enter a kicking duel with Lee Byrne, one of the players of the tournament so far, and winner of the RBS Man of the Match award for his two-try performance in Cardiff two weeks ago.
Following Kearney’s switch, Ulster’s Tommy Bowe moves from right to left wing and Leinster’s Luke Fitzgerald has been promoted to the replacements bench.
Ireland: Kearney; Horgan, B O’Driscoll (Capt), Trimble, Bowe; O’Gara, Reddan; Horan, Best, Hayes, O’Callaghan, O’Connell, Leamy, D Wallace, Heaslip
Replacements: Jackman, Buckley, M O’Driscoll, Easterby, Stringer, P Wallace, Fitzgerald