Alexander-Arnold came in to replace Nathaniel Clyne at right-back at Old Trafford, with Liverpool’s No. 2 suffering a rib injury that kept him out of contention.
Coming in for his first league start away to the Reds’ fierce rivals bore striking similarities to Rob Jones’ debut back in 1991.
While Alexander-Arnold didn’t shackle Anthony Martial quite as emphatically as Jones did Ryan Giggs all those years ago, he certainly acquitted himself well over the 90 minutes.
And speaking to Sky Sports after the game, Klopp could not hide his admiration for his latest debutant.
“An outstanding performance. Immediately against a player like Martial,” he said.
“What a boy he is. It’s good to help him and good that we can show him.
“The right full-back side is in good hands even when Clyney is not available.”
Alexander-Arnold made three successful tackles, two interceptions and eight clearances, keeping Martial quiet before the Frenchman was substituted just after the hour.
It was a mature performance from the No. 66, and one that can instil Klopp with confidence moving forward—particularly if Clyne’s injury keeps him out for any more games this January.
Echoing Klopp’s praise on Twitter, ex-Liverpool U23s manager Michael Beale applauded the decision to turn to Alexander-Arnold despite his inexperience.
“Congrats to Trent and the academy staff who prepared him for these moments,” he wrote.
“Also to the first-team staff for [having] huge confidence to play him.
“It’s great to see young players being given the biggest stage to play on. So rarely do young English players let anyone down. Youth = gold.”
Alexander-Arnold is likely to keep his place in the starting lineup for Wednesday night’s FA Cup third-round replay away to Plymouth Argyle.
If that is the case, the youngster has a great opportunity to build on this strong start and further convince Klopp of his quality for the long term—as he is a talent worth cherishing.