In the last week and a half, Liverpool have developed a new appreciation of the old adage that you don't know what you've got until it's gone.
Absent from the side for almost six weeks, Trent Alexander-Arnold retuned to the Reds' starting XI in the most testing of circumstances last week: a Champions League last-16 tie against Germany champions Bayern Munich.
The right-back found himself in direct opposition to Kingsley Coman and David Alaba, and he kept both Bayern stars quiet as Jürgen Klopp's men shut out the Bundesliga side, earning a 0-0 draw.
Then, in his first Premier League start since the 1-0 win over Brighton & Hove Albion on January 12, Alexander-Arnold was the catalyst to reignite a Liverpool attack derided after a 0-0 draw at Old Trafford on Sunday by producing three assists in a 5-0 midweek win over Watford.
In these two performances, the 20-year-old England international illustrated just how much he adds to Liverpool at both ends of the pitch.
With Nathaniel Clyne shipped out on loan in January, midfielder James Milner has been the man to fill in for Alexander-Arnold of late. The veteran former Leeds United and Aston Villa man's versatility is his biggest asset, but Liverpool's entire right flank suffers greatly when he is asked to deputise for the young No.66.
The defensive side of the game is where Alexander-Arnold has the most room for growth; he will continue to refine his positional instincts with time and experience. But the Bayern game showed just how far he has already come in this regard.
No Liverpool player made as many interceptions against Bayern as Alexander-Arnold, evidence of his developing anticipation, and only captain Jordan Henderson made more tackles.
What's more, Alexander-Arnold was still incredibly effective in attack against the Germans, getting forward to make 11 crosses and creating four scoring opportunities – no player on either side could match the Liverpool right-back in either category.
Against Watford, who posed much less of a threat to the Reds, Alexander-Arnold was completely off the leash. He received more touches (102) and created more chances (five) than any player on the pitch.
The quality of Alexander-Arnold's crossing was reminiscent of former England captain David Beckham. Like Beckham, Alexander-Arnold is not the kind of wide player who regularly dribbles around the outside of his opposing full-back to whip crosses in from the byline. And he doesn't need to. Instead, he has the rare technical ability to bend his crosses around the first defender and into the most dangerous areas.
He twice delivered for Sadio Mané to score against the Hornets, before claiming a third assist when his beautifully flighted free-kick was headed in by Virgil van Dijk.
Alexander-Arnold's technique on the ball has always made him a unique full-back, an unusual proposition for opponents due to his ability to act as a playmaker from an unorthodox position, employing the skills he honed as a midfielder in Liverpool's youth system.
With his defensive nous rapidly improving, he is on course to fulfil what many predicted of him upon his breakthrough into the Liverpool first team by becoming one of the best right-backs in the world.