Jurgen Klopp’s kids did him proud again as Lewis Koumas scored on debut and fellow 18-year-old Jayden Danns registered his first two goals as a depleted Liverpool side beat Southampton 3-0 at Anfield.

Victory, just three days after an exhausting 120-minute Carabao Cup final win over Chelsea, set up an FA Cup quarter-final at arch rivals Manchester United.

Whether the academy players will be required for that will depend on how fast the club can rehabilitate the 13 players currently injured in the next fortnight but regardless they have done their job.

Koumas, son of former Tranmere and West Brom midfielder Jason, was one of six players 21 or under in the team.

And it was one of his fellow academy colleagues Bobby Clark, one year his senior and making his 10th appearance, who supplied the assist just before half-time.

Danns, the son of former Crystal Palace midfielder Neil and who only made his debut at Wembley, came off the bench to score the second in the 73rd minute which allowed Anfield to breathe a sigh of relief.

That allowed Klopp the luxury of sending on Trey Nyoni, who at 16 years and 243 days became the club’s youngest player in the competition and third youngest in the club’s history.

That was the signal for the party atmosphere to kick in with the Kop singing “we haven’t won a trophy – since Sunday afternoon” – just before Danns fired home his second in the 88th minute after goalkeeper Joe Lumley parried Conor Bradley’s drive.

Southampton, however, were left ruing a missed opportunity against under-strength opponents having created enough chances in the opening half-hour to have made life difficult for their hosts.

Five of Liverpool’s Sunday starting XI – Caoimhin Kelleher, Virgil van Dijk, Harvey Elliott, Cody Gakpo and Bradley – were retained with three others – Ibrahim Konate, Alexis Mac Allister and Luis Diaz – dropped to the bench.

However, it was not all routine with defender Joe Gomez, who has been deployed all across the back four this season, asked to play the holding role in midfield alongside youngsters James McConnell and Clark.

But being asked to play a late cameo in a cup final and delivering from the off in a somewhat experimental team are two different things and the disjointed nature of the first 40 minutes were understandable.

Southampton, fourth in the Championship and with eyes on a bigger prize than cup success to the extent they made eight changes from Saturday’s defeat to Millwall, took advantage but not enough to open the scoring, which was largely due to their decision-making in the final third.

Sekou Mara had the ball in the net after just 38 seconds but had gone too early and was flagged offside.

Kamaldeen Sulemana hit a post and Mara forced Kelleher into two saves, with Sulemana then opting to shoot at the goalkeeper with Mara and Samuel Edozie waiting for a pass.

There was a point late in the half when Kostas Tsimikas was shouting instructions to Gakpo only for Klopp to tell the left-back to do something different when he had the ball.

It summed up the confusion and lack of cohesion – until a moment of clarity fashioned on the training fields of Kirkby broke the deadlock.

Lumley had waited 40 minutes to make a save, from Elliott’s 25-yarder, but he was undone by the quick feet of Koumas and a deflection off Jack Stephens.

Koumas started the move out on the left wing and when Clark picked out the winger’s run he cut onto his right foot and hit a shot which flicked off Stephens on its way past Lumley.

In a pre-planned move, Konate replaced Van Dijk for the second half to present Liverpool with a different challenge without the leadership of their inspirational captain.

The substitute assumed the mantle immediately, doing just enough to put off Mara as he tried to reach Sulemana’s cross, while at that same far post the unmarked Shea Charles fired into the side-netting with only Kelleher to beat after a corner dropped to him.

Danns showed a composure belying his age by clipping a shot over Lumley after Will Smallbone’s errant pass went straight to Elliott, before adding a late second.