Van der Flier: Small margins will be key to beating Clermont
Given the impact he has already had in his fledgling career, it is easy to forget that Leinster's win over Wasps in the Champions Cup quarter-final was the first professional knockout game Josh van der Flier played in.
The first of many, everyone would agree, but Sunday's test against Clermont Auvergne will be a step up after facing a Wasps team that really disappointed in the last eight.
Leinster are braced for a brutal battle up front and van der Flier's knows that he will have his work cut out at the breakdown if he is given the nod from the start.
Either way, the 23-year-old will have a role to play at some stage in Lyon and he is relishing the task that lies ahead.
"Watching them when I was younger, you'd be like 'Oh, there's nothing you can do about it', they're strong so they'll knock us back kind of thing, and they're fast," van der Flier explained.
"But when you're playing you kind of know ways - if we put pressure on them then they won't be able to do what they can do, so you use more of a practical way of dealing with them rather than 'This is what they are good at they're going to beat us in that area'.
"You've got to look at those, it is the finest of details, as you've seen from those previous games.
"So from doing video review or looking at the opposition and what weaknesses they might have, if we can get the tiniest of tiniest margins then that could be the difference in the games."
Like plenty of his young team-mates, this is very much uncharted territory for Van der Flier but the fearlessness with which Leinster have played this season is likely to stand in their favour against a powerful Clermont outfit.
"These are the games you're looking forward to for weeks," the flanker said.
"When I was younger, everyone was looking forward to watching them, fans were really excited to see them and of course, as a player you really want to be playing in them.
"The Wasps game was my first professional knockout game, so it was all new and it was pretty incredible. I was pinching myself to be on the pitch and playing in those games."
While last season's disappointments are very much in the past, the younger players in Leinster's squad have proven that they have learned lessons but the experienced campaigners have also been crucial in guiding them.
Leo Cullen's side are flying high in the Guinness PRO12 and even though there is an acceptance that an altogether tougher task awaits on Sunday, it was one that they do not fear.
"We had a young team on against Ospreys and watching it back I thought we looked pretty composed to be able to get the drop-goal," Van der Flier added.
"I think we have a lot of confidence. Especially all the younger lads coming in, they've been playing really well.
"I think we just have to look at it like another game, if someone is taking a kick they can't be thinking 'Oh this a semi-final, this is a massive kick', you've just got to play as if it's any other game, try play as well as you can and almost forget that it's a semi.
"Use the fact that it's a semi-final to motivate you but not to put you off your game.
"I suppose that's the best way to look at it."