He jogged over to Lewis Miley, the County Durham-born 19-year-old who, two years earlier, had became the youngest player to represent Newcastle United in Europe, and placed the armband around the teenager's bicep. The crowd roared their approval at what felt like a symbolic moment and Eddie Howe, after the match, hailed Miley as "potentially a future captain of the football club."
A few hours later, Miley is eating breakfast at the Magpies' training centre. "It was a big surprise," he smiles. "I saw Tripps come off and he said 'here, put this on.'
"It was a great feeling - and you heard the crowd afterwards which was even better.
"You don’t really think (about it) as much during the game - it's more after, really, when you see the photos and you're like 'I've just been captain in the Champions League!'. It's what I've dreamed of, since supporting Newcastle. It was a brilliant moment for me."
Trippier has 54 England caps. Now 35, he's won a La Liga title, played in a Champions League and European Championship final and, together with Guimarães and club captain Jamaal Lascelles, lifted Newcastle United's first domestic silverware in 70 years at Wembley last March.
It was Trippier who, as he and Guimarães climbed the 107 steps to the Royal Box, insisted that long-serving Lascelles should be part of that historic moment as he recovered from an anterior cruciate ligament injury. Passing the armband to Miley was a similarly powerful gesture, and just as spontaneous.
"In the moment, I just thought I'd give it to Lewis," Trippier explains. "I didn't expect it to sort of blow up as much as it did, but he's a local boy, Newcastle through and through, and it would have been a nice moment for him.
"People don't realise he's still only 19 years old, it's crazy how young he is, but I've said many times to him he will be future captain of this club. It's a good experience for him to take that responsibility.
"I can remember when I first had the armband. For me personally, I've always been one of those players where, whether I wear it or not, it doesn't really bother me, but it's a proud moment to wear the armband if it's for a minute or leading the lads out.
"But it's different when you're from Newcastle. It's different because it's Lewis Miley. He grew up here, as a Newcastle fan. I guess all his family were there watching; to see their son have the armband for Newcastle in the Champions League is an amazing occasion for the family."
Miley confirms: "They were all there, so it was even better. It couldn't be any better, really: playing at home, captain in the Champions League…".
Wednesday wasn't the first time Miley has captained Newcastle; he'd done so before at youth level as he came through the Academy he joined as a seven-year-old, and for the closing stages of a pre-season friendly win over Gateshead in 2023. Polite and reserved off the pitch, Miley nonetheless has a stature and presence which belies his age and on Thursday evening, less than 24 hours after wearing the armband, he was at Whitley Park to watch United's youngsters take on Crystal Palace in the FA Youth Cup.
"I think you don't always have to be a loud person, you can still be calm as well as being like that, and people look up to you," he offers. "Going to the under-18s game, I think it's a big thing, going to watch. Obviously my brother (Mason) was playing as well, so that was good.
"The players that captain, you look up to. They're big characters, big people you look up to and think 'that's the way I want to go.' Hopefully I can do that."
And in Trippier, Guimarães, Lascelles and the rest of the Magpies' leadership group, Miley has plenty of role models. "They're great to look up to," he says. "You see the careers they've had so far and I can only keep getting better playing with and looking up to people like that."
But however many times he captains his boyhood club in years to come, Miley will always remember the first time and he'll treasure the armband and shirt from that PSV fixture.
"I've kept them," he admits. "I think I'll get my shirt framed. It's something to remember; I was buzzing when it happened."
