Venue: Twickenham Date: Sun, 13 March Kick-off: 1500 GMT
Coverage: Watch live on BBC One Wales, BBC One HD and online from 1635-1900; Listen on BBC Radio Wales, BBC Radio Cymru & BBC Radio 5 live; Text commentary on BBC Sport website and mobiles
Shaun Edwards barks out instructions during a Wales training session
Shaun Edwards says Wales will need their biggest defensive effort of the campaign to stop Ireland's "expansive rugby" in Saturday's Six Nations match.
The defence coach has been "happy" with the commitment in defeat to England and victory over Scotland and Italy.
But he says the Irish, scorers of six tries in their last two games, will pose the most potent threat so far.
"We will have to up it a level against Ireland because they are scoring tries," said Edwards.
Wales came into the championship having conceded 11 tries in a winless autumn series against Australia, South Africa, Fiji and New Zealand.
Wing Chris Ashton scored twice as Warren Gatland's side opened with a 19-26 opening defeat to England, but a huge defensive effort denied Scotland a try a week later in the 6-24 victory in Murrayfield.
The defence was then breached twice as Italy pounced on mistakes to cross the try line in Wales' 16-24 victory in Rome.
Edwards stressed Wales cannot afford any such lapses at the Millennium Stadium against Ireland, who are second only to England in the most tries scored category this season.
"Ireland were red-hot in the first half against Scotland and they also scored three tries against France, which was an exceptional effort," said Edwards.
Our penalty count has been high against us because we have been tackling for long periods of matches
Wales defence coach Shaun Edwards
"While they struggled a bit with their handling in Italy, they still created a number of chances. They are playing expansive rugby and scoring tries.
"It will be a big ask for us defensively but we feel we are up to the challenge. I am very happy with the way our defence has gone in the last couple of games."
Apart from a sound defence, Edwards believes that the key to Wales' hopes of beating Ireland at home for only the second time since 1983 will be improved discipline.
They have so far conceded 40 penalties and free-kicks in this season's championship and collected three yellow cards - more than any country on both counts.
"Discipline is going to be important," said Edwards. "Our penalty count has been high against us because we have been tackling for long periods of matches.
"Possession-wise we have lost the battle in most of the games, certainly territory-wise, and we have been defending our own 22.
"More penalties are given against defending teams now than attacking ones, which I totally agree with even though I am a defence coach.
"Defences should be refereed more harshly than attacks, which was not the case 18 months ago when we were getting 'kick-fests' in every game.
"We will be defending with a lot of vigour and aggression and within the rules of the game. We have a powerful kicking game and you need that against a team of Ireland's understanding, playing in the right areas.
"Teams are not scoring tries from 50 or 60 metres against us, so we have to get the ball in their half."
Edwards also expects the vastly experienced Ronan O'Gara to keep Ireland's number 10 shirt, following his impressive display after being preferred to Jonathan Sexton against Scotland last time out.
"They have an option at fly-half with Sexton and O'Gara, who are different types of players," former Great Britain rugby league international Edwards added.
"I expect O'Gara to start after the way he played against Scotland. He is in good form, but if he does not start we will have to adapt later in the week.
"If you are an international fly-half you are going to be a pretty good kicker and Ronan O'Gara is an exceptional one."