Wales coach Robin McBryde believes that Paul O'Connell is currently among the best locks in the world, as he prepares to make his landmark appearance for Ireland.
The 35-year-old is in line to pick up his 100th cap on Saturday afternoon when he leads out his country at the Millennium Stadium.
"He's pretty much up there at the moment [in terms of the world's best locks]," forwards coach McBryde told reporters. "It's a different Ireland team without O'Connell playing in it.
"He's a real talisman not only for his country but club as well. The players who have worked alongside him with the British and Irish Lions have commented on how hungry he is to keep on learning. He reads the game well and knows exactly what to do - I don't think there's anyone better in that role."
The big showdown in Cardiff will also prove to be a special occasion for Wales star Sam Warburton, who will captain his side for a record 34th time.
McBryde has hailed the Cardiff Blues flanker ahead of the must-win game against Ireland, claiming that his leadership style rubs off on those around him.
"There's different ways of leading, and each captain has got their own way of leading the team," he told reporters. "He's not the most vocal and tends to only speak when he has something to say.
"Some people are given the captaincy and you can't shut them up from the word go. You know when Sam speaks that it is going to be something relevant. He's come under pressure at times, but he's handled it. He simply focuses on the game in hand and that will be the case tomorrow."
Wales need to win if they are to keep alive their hopes of claiming a third Six Nations crown in four years, while Ireland are still on track to lift an impressive Grand Slam with a victory of their own in South Wales.