Joe Schmidt explained on Thursday that Ireland scrum-half Conor Murray's shoulder bruising was the reason for leaving him out to face England.
Murray had trained fully earlier in the week but the Munster number nine showed signs of concern in Thursday's practice, leading to Schmidt's decision to start Kieran Marmion.
“Conor, he trained okay on Tuesday without contact. We fitness-tested him today and just felt that he wasn’t going to be quite 100 percent," Schmidt told The42.ie
“Not that he couldn’t function, just that once contact came back in and he got more bruising on top of bruising on that shoulder, we just felt that if we lost him early in the game, then you’re vulnerable.”
Murray has been a key figure for Ireland in recent years and his absence means that Marmion wins just a second start for Ireland at scrum-half, with his first coming at home to Canada last November.
Highlighting what Ireland will miss with Murray's absence, Schmidt highlighted the gap in caps between Ireland's Marmion and Johnny Sexton to England duo Ben Youngs and George Ford; a margin of 80 (68 of which belong to Sexton) to England's 105.
“You lose his experience, 50-plus caps, you lose his calm. He’s incredibly calm on the pitch. He’s a good foil for other players who are under pressure, because he very seldom looks like he’s under pressure.
“You lose a defender who is incredibly good at organising other people and himself to make very good decisions, and then carry them through with positive action.
“His ability to control us and navigate us around the pitch, particularly with his kicking game, and the speed of his passing game.
“His experience will leave a hole for us, we’ve got a combined caps with Kieran Marmion and Luke McGrath of about a dozen, as opposed to about 140 that they have in their half-backs.”