Ireland captain Paul O'Connell has lavished praise on Wales head coach Warren Gatland ahead of Saturday's meeting in Cardiff.
O'Connell played under Gatland on the British and Irish Lions tour to Australia in 2013 and has plenty of respect for the New Zealander.
The lock looked back on the times when his Munster side faced Gatland's Wasps in European action.
"I think he's an incredible coach: for as long as I can remember we've being trying to poach ideas from Warren Gatland," said O'Connell.
"We played Wasps with Munster in 2003 or 2004 and they were so far ahead of anything any provincial or club side were doing.
"It was a rude awakening for that day with Munster. It was the same when we were on the Lions in 2009. We tried to bring so many of the things that he had in the set-up there back to Ireland and back to Munster.
"His record is incredible, it speaks for itself. He's a terrific coach, a great guy, a very clever coach, and kind of like Joe [Schmidt], they are both a little bit ahead of their time."
Elaborating on the similarities between the two coaches, O'Connell highlighted their shared ability to simplify the game at Test level.
"They've different ways of going about things but one of the big things both of them do is they make what seems complicated very simple," added O'Connell.
"When you're playing an 80-minute rugby match I think players are generally exhausted or close to exhausted when they're playing and the simpler you can make things the easier it is to be good at it, the easier it is to be aggressive at it.
"I think Warren probably pioneered that way of thinking.
"But they're very similar in that they're just ahead of the game all of the time."