Ethan Ampadu and the other bright young things who shone for Ryan Giggs on Thursday night have been told they must keep their sparkle.
Having helped Wales thrash the Republic of Ireland 4-1, the foursome who made their first competitive starts – Amapdu, Connor Roberts, David Brooks and Chris Mepham – have set an impressively high standard.
It’s one that their manager wants them to maintain as they face Denmark on Sunday in their second UEFA Nations League match in Aahus.
That game is now likely to be an appointment with a full-strength Danish team after a dispute about players’ commercial rights was resolved.
“It’s a difficult match with a very good team on Sunday,” said Giggs after his bold selection had paid handsome dividends.
“We don’t know what their preparation has been like, but we expect a tough game, their best 11, and they are probably favourites in the group.
“We might have to play even better to get that result. I said to the players the bad news is you have to keep to that standard. They have to keep getting better, keep improving.”
All four of the Wales youngsters looked comfortable enough to keep their places under Giggs, who in one swift and decisive conclusion appears to have moved on quickly from many of the team who carried the country to the Euro 2016 semi-finals.
Chris Gunter, James Chester, Andy King, Joe Ledley and Sam Vokes were all relegated to the substitutes’ bench as the new breed made their mark.
Of those, Ampadu – still only 17 – was the stand-out performer. From the moment he sprayed out his first pinpoint pass with an easy confidence, to the crunching tackle and driving run that set up Aaron Ramsey’s goal, the Chelsea player’s influence was stunning.
Just to highlight what an all-round talent he is, it was Ampadu who later showed his strength in defence to win the ball and clear, just when Ireland looked about to score.
No wonder the Irish media inside the Cardiff City Stadium were cursing their own association for what they felt was a half-hearted attempt to persuade Ampadu to take up the offer of his Irish qualification.
Giggs had warm words for Ampadu – who looks just as comfortable in the Premier League as an increasingly favoured choice at Chelsea – but also for his more established talents such as Gareth Bale.
The manner of the performance, with Ampadu and Brooks excelling and Bale at his brilliant best, gave a tantalising glimpse of the bright future that could lie ahead under Giggs.
“I talked about expressing themselves and trusting each other, and that’s what I got,” Giggs said.
“We could have scored more, but to get four in any game is special.
“Credit to ourselves, not many teams could have lived with us tonight. I think we’d have given anyone a game.
“The young lads came in and did well, but I feel we have got 30 players who can be in the first XI. I never had that when I played for Wales.
“Every time Gareth plays, he makes a difference, whether it’s for Wales or Real Madrid. It gives everyone a lift, but he’s a great example of the level you have to get to.
Republic of Ireland boss Martin O’Neill had no complaints about the result after seeing a team missing a handful of regulars taken apart.
“We were well beaten in the game,” he said. “We were second best for pretty well all of the evening.
“We made more than a few mistakes. We allowed room for world-class players, and particularly Gareth Bale, to work his magic.
“He is a world-class player, and I do think it helps when you have got a world-class player at your disposal. He is capable of unlocking defences, he is capable of scoring the type of goal that he did, and he is playing for Real Madrid as well.
“We were missing some really key players tonight. Fine. This was a really tough evening for us, regardless of whether we had some players missing, and we should do better.
“It has not diminished my enthusiasm for the job one jot. We’ve a long, long way to go, and we might have one or two players back for the games in Dublin.”