The Leicester Tiger has always performed better for Eddie O'Sullivan's side when positioned at 15. Of Naas-born Murphy's 13 test tries in 26 appearances, eight have come from full-back.
Throw in his seven touchdowns in 15 games for Zurich Premiership leaders the Tigers this term, and you cannot ignore Murphy's call for a role at 15.
Murphy scored twice against the US Eagles when last at full-back, and his danger from deep was certainly missed during the 2003 World Cup, when injured.
With Ireland having scored 22 tries in their five previous clashes with Italy since 2000, O'Sullivan - facing his fourth Six Nations, and now the second most-experienced coach in the tournament behind Bernard Laporte -has obviously plumped for a the attacking skills of Murphy to add that X factor to the backline. Dempseys exclusion from the starting side was a tough call. Whether this is a permanent move, it is unclear, but one thing is for sure, the switch has as much to do about Murphy's pace and footballer's brain, as the men who will line out immediately in front of him on Sunday.
Gordon D'Arcy's return to the side - having missed the three Autumn internationals - is a welcome sight, with the 2004 Six Nations Player of the year back to form following a groin injury, sustained in October.
From his dancing December second-half brace for Leinster in Bourgoin before Christmas, to his bullet-proof performance at last week's Six Nations launch in London, captain Brian O'Driscoll is certainly in peak condition.
His provincial team mate Shane Horgan has been Irish rugby's assassin-in-chief of late, bagging ten tries in 12 games for Leinster so far.
His international haul of 12 in 34 caps should be fortified also, especially with a regular spell in the number 14 shirt. The 26-year-old was in a midfield tandem with O'Driscoll when facing Argentina last November.
More than anyone, this campaign could be about the duo of Murphy and Horgan and how their partnership in a new back-three initially finds it feet.
Dempsey has rarely had a bad game for his country - starting all ten of Ireland's tests in 2004. O'Sullivan knows both full-back and openside flanker were marginal decisions today.
''Girvan has not really done anything wrong, and it was a very difficult decision to make,'' said O'Sullivan.
''The back-row was always going to be a hard one to call because of what we have available. Denis (Leamy) got the nod. He is good going forward and a good ball carrier.''