Host of Liverpool stars shown up by inexperienced kids in West Ham defeat

But first the dark night. And nights are never going to come any more bittersweet than this for Liverpool: heartbreaking FA Cup defeat in a tie which saw a young, makeshift team go toe-to-toe with one of the Premier League's better sides. You can make a case for West Ham as deserved victors: they did have two bona fide penalty shouts turned down over the 210 minutes of the tie, after all, and won last night's woodwork count by two unfortunate bangs to one.

But you can make a hearty case for Liverpool as well. Nobody gave this young team an earthly before kick-off at Upton Park, especially with a central defensive partnership, cobbled together at the last minute, of Lucas and Tiago Ilori, and an 18-year-old in Pedro Chirivella covering in centre midfield. Yet there they all were, pushing West Ham to the limit. Lucas and Ilori were as competent a centre-back pairing as Liverpool has seen all season - admittedly not a high bar, but still. Meanwhile Chirivella played with a confidence and assurance all out of whack with his age and experience.

While Klopp's stoic post-match mood may or may not have been affected by seriously good post-op painkillers, he's entitled to concentrate on the sunny side nonetheless. The big matzo ball of the result aside, there were mainly plus points to take away. Lucas emerged as a credible contender for a stopgap centre-half, much in the same mould of Daley Blind at Manchester United, tenacious midfield nous utilised to settle a defensive work-in-progress.

Ilori, prematurely written off by some after failing to break into a dreadful Aston Villa team while on loan, proved himself a level-headed, ball-playing presence, breaking up several attacks by stepping in with a calm anticipation. Jon Flanagan, who flagged severely in the League Cup semi-final against Stoke City, kept motoring, suggesting he's on his way back after that long lay-off. The equally energetic Brad Smith occasionally left huge gaps at the back, but was an utter menace on the overlap going forward. It shouldn't be impossible to coach a little more defensive discipline into an emerging player; attacking savvy, on the other hand, comes at a premium.

In the midfield, Kevin Stewart proved as tenacious as Chirivella. The pair offered more than adequate cover for their new centre halves, who in turn seemed to make Simon Mignolet appear less jittery. The under-fire keeper couldn't be faulted for either of the goals, made a couple of blinding saves, and generally commanded his area like a 27-year-old, six foot four, international keeper should. Mignolet is often cited as the reason Liverpool's defence is constantly so ramshackle. While he's got a long way to go to win trust back, here was an argument that it works both ways: without the woefully out-of-form Mamadou Sakho or the eternally nervous Dejan Lovren flapping around in front of him, there was less for the keeper to concern himself with, more scope to go about his business unfettered.

Meanwhile up front, the biggest positives of all: Philippe Coutinho and Daniel Sturridge are available once more. Both took turns to wind their way along baroque routes in attack, giving Liverpool some of the unpredictability they've been sorely lacking during recent weeks. Even poor old Christian Benteke showed some marvellous touches in his link-up play - one dragback on the byline to set up Jordon Ibe was straight out of the Peter Crouch good-touch-for-a-big-man playbook - but unfortunately several misses spoil his report card. He can't go on missing chances like this.

Plenty of positives, then. But every action has an equal and opposite reaction, and much of this spells bad news for the likes of Sakho, Lovren, Jordan Henderson, Adam Lallana, Emre Can, Joe Allen and Alberto Moreno. All first-team regulars who have repeatedly failed to take their chances to shine this season; all of them shown up by inexperienced kids who seized a rare opportunity to impress in the oldest and grandest competition in the world.

Klopp can only clear out so many players in the summer - the wise money suggests reprieves for Can and Allen, and probably Henderson if he can get fit, keep things simple, and forget the Steven Gerrard Tribute Act stylings - but few of the first-team regulars have been making strident cases for long-term inclusion, Roberto Firmino apart. This needn't be the end of the world. Liverpool's wait for another FA Cup will extend past a decade now, but last night Klopp may have realised that he's got more options in his squad than previously thought.

That should give the manager wriggle room to concentrate on a couple of marquee signings for next season, rather than spreading a limited budget on a complete squad overhaul. The future could indeed be sunny: it's up to a few first-teamers to decide whether they want to bask in it. The kids have thrown down a gauntlet.