It was the kind of performance to define a player.
Doing so with distinction, too.
There were heroes everywhere during the Reds’ epic 3-0 first-leg victory over Manchester City, but the teenager’s showing was a remarkable one. Handed the sizeable task of stopping Leroy Sane, the young Scouser delivered, big time.
Even more impressive perhaps, is the fact that Alexander-Arnold’s biggest performance for Liverpool came after his toughest few weeks. The Premier League is an unforgiving environment, and the young right-back has been under the microscope of late. They might not admit it now, but plenty feared for him before Wednesday’s game.
A bad afternoon at Old Trafford, in which he was given a torrid time by Marcus Rashford, was followed by a similarly tough day at Crystal Palace against Wilfried Zaha last weekend. Defensively, the spotlight was on him.
For Neil Critchley, who coached Alexander-Arnold at U18 and U23 level at Liverpool, it was no surprise to see him come out fighting.
“I thought it was a really top performance from him,” says the current Reds’ U23s boss. “He's had a bit of criticism recently and I thought he answered his critics in emphatic fashion.
“It was a different type of performance from him. You associate Trent with flying forward and getting crosses in, but because of the game he did very little of that. He was questioned with what he's been questioned about - his defending. He had to do a lot of it and I thought he did it extremely well. I was delighted for him.”
Critchley revealed that Alexander-Arnold had returned to Liverpool’s Academy complex in Kirkby after the United game last month, speaking with Academy director Alex Inglethorpe to request advice and guidance. It is a measure of the teenager’s maturity and humility that he felt comfortable doing so.
“He and Alex have a very good relationship, so he came in to speak to him,” Critchley said. “I speak to him but it is just support. That is all that it is. As he gets older he might ask for a little bit more advice ‘what do you think?’ and then you might give him your thoughts, but you don’t want to step on anyone’s toes or give mixed messages. It is just ‘keep going, keep doing it’, support and guidance.
“He still sees himself as one of us. He came through the Academy so he still sees himself as part of the family here. I don’t think he sees himself as an established first team player – yet. And I think that is one of the best qualities he has. He doesn’t think he has made it. He doesn’t think ‘I don’t need you, I don’t need to listen to you now’. That is what makes him the player he is and hopefully the player he will become.”
Critchley believes Alexander-Arnold’s progress, and the hiccups along the way, serve as the perfect example to the next crop of young hopefuls looking to emerge from Kirkby. Top-level football tests even the most talented and the most brave. The U23s boss, though, believes Jurgen Klopp deserves credit for sticking with the youngster through his tough spell.
“The easy thing after Trent’s last few performances was to leave him out,” he said. “He didn’t and Trent paid him back last night, he repaid him, and I wish there were a lot more managers in the Premier League who showed faith in young English players like that because there are more players like Trent who just don’t get that time, that faith, that trust. I was delighted.”
He added: “A young player’s development is like a roller coaster, it is up and down. You are talking about a handful of players in the last 20 years whose careers have just gone straight up.
“The true test is when you get that little bit of criticism then you have to respond and show what you are about as a player. The best ones do and Trent did that last night.
“But like I say it is only one game. He did very well last night but there are some big games coming up and he needs to go again. Fingers crossed he can reproduce it. I have no doubt he can.”
Alexander-Arnold was not the only academy graduate in Liverpool’s matchday squad against City, with 19-year-old centre-back Conor Masterson named among the substitutes for only the second time in his career.
And with injuries mounting, the Dublin-born defender will be hoping to feature in the squad again this weekend as the Reds take on Everton in the Merseyside derby.
“I spoke to him yesterday before the game,” Critchley revealed. “We knew the day before he might be on the bench.
“Whether he's with us for our game (against Arsenal) on Friday night we shall see, but fingers cross he will still be involved with the first team for the derby on Saturday.
“It was great to see him warm up. That will be a big moment for him and his family, just to be involved in that environment, to see the preparation for a game of that magnitude will be such a great learning curve for him.
“He's very level headed. He doesn't get carried away, he takes everything in his stride. You see that when he plays - there's an assurance about him.
“Like Trent, these young players have a belief in themselves. Conor won't have been thinking 'what am I doing here?' He will have thought 'I can do this, given an opportunity'.”