Ireland coach Joe Schmidt has recognised that the absence of injured scrum-half Conor Murray will be sorely felt during Saturday's Six Nations clash with England.
The 27-year-old has been unable to shake off the shoulder injury that forced him from the field early in the second half of last week's 22-9 defeat at the hands of Wales in Cardiff that proved costly for Ireland's championship hopes.
Murray's replacement, Kieran Marmion, will make just his second Test start at the Aviva Stadium, while bench cover will be provided by Leinster's Luke McGrath, who has only one international cap to his name.
And Schmidt acknowledged how much his side will miss the presence of Munster star Murray as Ireland attempt to thwart England's attempts for back-to-back Grand Slams.
"You lose his experience, 50-plus caps, you lose his calm," he said. "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.
"And you lose 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 total with Kieran Marmion and Luke McGrath of about a dozen, as opposed to about 140 that they [England] have in their half-backs."
Rob Kearney will also be missing for the hosts after suffering a knee injury, with Jared Payne slotting in at full-back, while Iain Henderson has been preferred to Devin Toner in the second row.