Comment: How can Liverpool move forward with a flaky defence?
Klopp's case for positive football leaves fans looking back with regret
Liverpool are a crimson tide going forward, but a red warning light at the back. The question people ask of them in the Premier League will not change in Europe. They will succeed or fail on their ability to balance enthusiasm in attack with concentration and structure in defence.
Any team that beats Arsenal 4-0 in one game and loses 5-0 to Manchester City in the next is not suited to the quiet life. Nor is one that concedes a soft goal inside five minutes on their return to Champions League football.
The kind of drama Jurgen Klopp's Liverpool lay on for their fans is wonderful when the result drops the right way. When it goes wrong, Anfield will find itself crying out for a bit more organisational rigour around their own goal.
But what a force they are when they attack together, sprint upfield, spread wide, invade the opposition's penalty area. Even without Philippe Coutinho, their £130 million (€144m) captive who started on the bench, they threatened to overwhelm their Spanish guests in the first period. After Dejan Lovren had missed his kick on a cross into his team's six-yard box, and allowed Wissam Ben Yedder a tap-in, Liverpool set about rectifying the error with impressive zeal.
They were in no mood to repeat the indignity of Basel two summers ago, when Sevilla took them apart in the second half of a Europa League final.
This time, Liverpool exuded confidence that they were the superior team - and led 2-1 at the break, after Robert Firmino (or Bobby Firmino, as the Kop know him) had missed a chance to make it three, striking a post with his penalty. But we all know what happens when a team miss opportunities to be much further ahead. The opponent punishes them. As witness - Joaquin Correa's 75th minute equaliser.
As we saw for parts of last season, Liverpool are a formidable attacking force, when they find their rhythm, and the midfielders behind play their part with strong tackling and constructive passes.
If Jordan Henderson does most of the dirty jobs, Emre Can and Georginio Wijnaldum drive on, when the chance presents itself. With that support, Firmino can take up goalscoring positions and Sadio Mane and Mohamed Salah can push through in wide positions.
All this, initially without Coutinho, who is being nursed back into the side, and Alex Oxlade-Chamberlain, who could end up as a squad player here unless he can find a position - and finally fulfil his promise. On this evidence you would not pick him ahead of Can, Henderson and Wijnaldum, or as a wing-back, especially as he appears not to want to play in that position.
Mane and Alberto Moreno were a handful for Sevilla on Liverpool's left flank, and no team can relax against Salah on the right, however one-footed he is. This blend of threats encouraged the sense that Liverpool have progressed more than Sevilla since that emotionally bruising night in Basel. Until Correa struck back, at any rate.
The 5-0 defeat at Man City sent tremors through this club. It could not be passed off as a freakish event, because Liverpool were so easy to pass straight through. Klopp's defenders are usually the ones who take the heat for messing up at set-pieces, but at City the problem seemed to go deeper.
Liverpool seemed oblivious to the threat of top-class passing and movement.
The failure was collective. But no club has used European football to re-energise the soul quite like them. To fans of other clubs, the whole Anfield 'European nights' routine must sound a bit over-done. But be assured: when overseas clubs come here, memory and tradition come bursting out on auto-release, and a higher destiny beckons.
With that European heritage now comes a very European coach, known for a particular achievement, and a specific style, at Dortmund, where the individual quality of his defenders was higher. It would be insulting to say he has only one idea about how the game should be played, but he sure as hell has a preference for mass counter-attacking and playing in the opposition's half.
As the clock ran down, the elation of the first half gave way to frustration, as an impending victory turned into an annoying draw. This is another skill for them to develop: the ability to close out games. At no stage, when Liverpool were 2-1 up, did you think they would settle for that outcome. They are programmed to keep hunting for more goals. Again, entertainment is not in short supply, but the risk level increases. Good work is wasted and the supporters go home grumpy. Progress becomes jerky.
The abiding memory from this Group E opener is that Liverpool were relentlessly positive. This level of enthusiasm is Klopp's religion. The big question is how far it can take them.
Not far enough, if they defend less well than they attack. (© Daily Telegraph, London)