Stuart Lancaster is preparing England to face the Six Nations' most complete side when Ireland visit Twickenham on Saturday week.
Brian O'Driscoll's men have swept aside Scotland and Wales to retain hope of completing the Grand Slam, with France the tournament's only other unbeaten team.
Lancaster admires an experienced starting XV packed full of British and Irish Lions that he believes is well coached.
"Ireland are becoming the most complete the side, definitely, because they've clearly improved in their forward play," England's head coach said on Wednesday.
"John Plumtree is their new forwards and defence coach and you can see the improvements they've made in that area.
"Their mauling game, as we saw against Wales, was excellent, so technically they're very good."
Lancaster confirmed that wing Marland Yarde, centre Manu Tuilagi and fullback Ben Foden were close to making returns for their clubs after lengthy spells in the treatment room.