Dejan Lovren and Liverpool introduce us to the art of un-defending | Barney Ronay

The humane thing to do, looking back on this exhilaratingly open 4-1 Wembley victory for Tottenham Hotspur against Liverpool, would be to focus on the ruthlessness of Harry Kane, the brutal speed of Spurs’ counterattack, the running of Son Heung-min.

Things are rarely that easy, though. In Germany they have a concept called Ruinenlust, which describes the irresistible pleasure of seeing a deeply distressed object in the process of falling to pieces. And for half an hour here Liverpool provided something similar as Jürgen Klopp’s team produced collectively one of the worst displays of elite-club defending the Premier League will see this season; and individually a candidate for worst half-hour on the pitch in recent memory.

Dejan Lovren has been thoroughly eviscerated by now, not just on social media and in on-the-whistle match reports, but by his own manager, who stated, rather cruelly, that he could have done better himself just wandering around Wembley in a pair of trainers.

And make no mistake, this was a horrendous half-hour from Lovren, who appeared at times to have completely forgotten he was actually playing in a football match, startled to find himself in the middle of all that green, so many faces in the crowd.

Nothing happens in a vacuum, however. Exactly why and how Lovren was quite this awful, so bad his awfulness itself feels like an event, a happening with its own sheen of beauty, is the real issue Klopp must attempt to address.

Lovren came to Wembley having played out 314 minutes without conceding a goal for club and country. Liverpool came here having kept successive clean sheets. And yet there was no surprise whatsoever in their defensive collapse against some high-grade attacking play, just a feeling of an axe being taken to a rickety and woodwormed fence.

First, though, the horror. It took four minutes for Tottenham to open the scoring. It was a beautiful striker’s goal, Kane springing on to Kieran Trippier’s dinked pass, working the ball on to his left foot, then thumping it low and hard into the corner.

Even in real time, though, it was impossible not to feel the eyes drawn to Lovren who produced a genuinely scene-stealing piece of un-defending. Lovren did not just lose Kane, he seemed to lose all concept of what it was he was doing here, dressed in these strange red clothes, ambling about like a man recently winched up off the anaesthetist’s table, and watching on with only the vaguest curiosity as the ball floated over his head into Kane’s path.

If the first Tottenham goal was helped by a horrible mistake from Lovren then, well, so was the second – albeit with the benefit of illuminating what was also a terrible goal to concede as a team. Credit to Spurs, who sent the ball the entire length of the pitch in two passes. But there was very little resistance to this as a basic idea. From a corner Hugo Lloris hurled the ball out to halfway. At which point Lovren felt the music swell, the choir begin to purr and coo and for just one tiny, fatal moment really did seem to believe he could fly.

It was a poor decision. Lovren launched himself. The ball floated in a gentle parabola over halfway. Lovren floated in a gentle parabola under the ball, Kane sped away and offered the perfect pass for Son to finish. You can only play the loopy central defence in front of you, but Tottenham had been utterly clinical. Moments later it was almost three, with another attack down Lovren’s no-fly channel. The ball floated over Lovren’s head in an eerily familiar echo of what had passed before, a case of Dejan Vu. Son spanked it on to the bar. And so it carried on, the white shirts seeming to treat Liverpool’s No6 as a minor piece of street furniture to be swayed around without much thought en route to somewhere else.

With half an hour gone Lovren was euthanised from the pitch, wandering off straight past his manager to sit three rows back, looking utterly stunned, still in his red shirt. Has there been a worse half-hour from an international‑standard Premier League player?

And yet to see this as simply a Lovren story, as Klopp has in the past, complaining that the problems with his defence are not structural, but a matter of individuals making bad decisions, would be misleading. Liverpool are well capable of conceding weak goals without Lovren, as they did here for the fourth and as they did while shipping five at Manchester City last month.

Lovren has looked and felt exposed at Liverpool ever since he got there, playing often in front of a midfield that leaves large, open green spaces. Emre Can and Jordan Henderson have an unfortunate case of shared weaknesses. Neither is quick to the ball, as Premier League central midfielders must be. Neither has the will or the discipline to sit deep. Even a world-class centre-half would be exposed behind them. And Lovren is not a world-class centre-half. He will take the unkind headlines. But Liverpool’s defensive holes are a collective phenomenon, just as Klopp, trainers or otherwise, must stand alongside his central defence on days like these.