For Leinster this week it will be a case of out with the new and in with the old.
More or less, anyway.
The youngsters and reserves who put down such an impressive collective performance and result away to Glasgow in the Guinness PRO14 last Saturday have made their case - yet again - but it will be the bulk of the old guard on duty when Heineken Champions Cup duties resume this Saturday over in Franklin’s Gardens.
Leinster will shape that narrative differently, of course.
“Maybe that’s the way you might see it from the outside,” said assistant coach Felipe Contepomi. “The way we see it is that we had a block of games and we want to put out the best Leinster team for every game.
“We are lucky and wealthy in terms of how tough the competition is within the squad. For us it is not a question of just setting up a team. We want to put the best and the strongest team on the pitch every weekend. That’s what we are trying to do.”
Leinster’s ‘B’ team was more than strong enough to account for Glasgow that, while divested of most of their own internationals, sprinkled a tad more experience through their ranks.
A ropey first half-hour aside, it was about as smooth a run as an away side can expect at Scotstoun and yet Devin Toner was the only starter who comes close to ‘first-choice’ status.
This next-generation has been making a name for itself all season, and Cian Kelleher was the headline act with two tries this time, but more notable than the raft of wannabes on the teamsheet in Scotland was the absence of Ronan Kelleher and Max Deegan’s names.
They seem primed for the meeting with Northampton this time around.
The future for them is now.
Leinster have some worries over Josh Murphy (head) and Peter Dooley (knee) as a result of the Warriors win but they are minor headaches in the greater scheme of things.
Leo Cullen has a bulging squad that is mostly fit and replete with option all over the park. Moulding the old and the new may be his biggest headache of all.
“It’s looking to various aspects, not just one, in each position,” Contepomi explained. “Fitness-wise, skill-wise, mentality-wise, how every player is. We try to fit in the best player to make the job for that game and that we do it with every position.
“That’s our aim. It’s hard, it’s not easy, but the way the guys got the victory in Lyon (in round two of Europe), how I see it, and the way they got it in Glasgow were similar ways.
"Really good strong defensive performances and taking the opportunities when we have them and a lot of character.” Northampton will ask different questions.
Their rout of Leicester at home over the weekend sees them sit on top of the Premiership as we enter another two-week block of European fare. Like Leinster, they are two-for-two in the Champions Cup and they are playing an exciting and effective brand of rugby.
The English side has scored more than 30 points in four of their last six fixtures in both competitions and Leinster have conceded 55% possession to both Lyon and Glasgow in their last two games. A concern, maybe?
“I wouldn’t be worried if we can defend the way the we did the last two games, but sometimes the games flow like that and you need to be able to win games defending and scrapping them out,” said Contepomi.
“Our objective is definitely to dominate and have more possession, territory and everything in the stats and try to set up ourselves to play a really good rugby style.
“Sometimes, the games are not like that, especially at this time of the year with the conditions that are hard to play in.
"You need to learn to win the games in a tough way. I wouldn’t be worried, we just need to get better at both ends of the game. Defence and attack.”