IT MAY have been through the back door of a qualifier, but it was still a grand entrance.

Liverpool's eagerly awaited return to the Champions League was so full of attacking brio that a potential spectre at this Anfield feast was being downgraded to Coutin-who?

The Reds didn't need their wantaway Brazilian maestro against a mediocre Hoffenheim, but the debate as to whether they should accept Barcelona's next offer for him has only intensified.

And it is a measure of the home side's performance - exhilarating in attack, still shaky in defence - that the argument for selling him has surely been bolstered.

The German side were more accident-prone at the back than Liverpool, but even Europe's heavyweights will be hard pressed to cope with the pace and cutting edge of Mohamed Salah, Roberto Firminho and Sadio Mane.

We all knew that attack is Liverpool's forte and, on this evidence, it looks as if they can manage without Coutinho as well as long-term injury victim, Adam Lallana. Just as glaring, however, was the need for reinforcements in defence.

Dejan Lovren has reverted to the sloppiness and uncertainty he showed when he first arrived while Simon Mignolet made you wonder why no attempt was made to buy Jordan Pickford from Sunderland.

Although you can see the front three – let's call them SFM – troubling the best, they may not score enough to compensate for the deficiencies at the other end.

Which is why, perhaps curiously - but football is seldom short of irony - another triumphant European night may well have edged Coutinho towards the exit door.

So far, Liverpool have been admirably firm in rejecting Barca's overtures.

Bolstered by the absence of a release clause, they see no reason to back down and lose another star.

The Fenway Sports Group are trying to build more than a new Anfield: they are trying to rebuild Liverpool's reputation as one of Europe's giants – and dispel the notion they are a selling club.

A major unknown in all this is how Coutinho would react if denied the chance of a dream move to Catalonia. Conflicting reports only muddy the waters but there has to be serious doubt as to whether he would knuckle down and produce an annus mirabilis as Luis Suarez did in similar circumstances.

The Brazilian is an introvert and appears to be sulking. His 'recovery' from a back injury but switch to an unspecified 'illness' only raises suspicions about the state of his mind.

Just what is he suffering from? And with every player demanding a move seemingly falling prey to this mystery virus, you wonder if the World Health Organisation has been alerted.

Seriously, Jurgen Klopp, who has been put in an impossible position over this, clearly wants to keep him as do most fans. But a growing number are suggesting that if Barca do come up with an 'insane offer' of close to £140 million (RM767.98 million), Liverpool would be equally insane to turn it down if they could get Virgil van Dijk with half of it.

Klopp appears more sanguine about his defence than almost anyone else. But when he lead the chase for the Dutchman early in the window he showed too much enthusiasm, incurring a wrap over the knuckles for tapping him up.

Perhaps it's a case of once bitten, but Chelsea are also keen and the player has declared a preference for Anfield. Denying the Blues a chance to shore up their own rearguard only makes getting Van Dijk more appealing.

But there are alternatives and not everyone has a Neymar premium on their heads. One going for a song at £20m and well-known to Klopp is Benedikt Howedes who is entering the last year of his contract with Schalke.

An experienced Germany international, Howedes looks a no-brainer to solidify that rickety back four and he's even had experience of playing alongside Joel Matip.

If Mamadou Sako really has burned his bridges and the rescue boats as well, then one or both of Van Dijk and Howedes must surely be brought in. And if Klopp still needs convincing he should stiffen his back four, on Sunday another wantaway South American superstar will be happy to oblige.

Alexis Sanchez has returned to Arsenal training, and it will be fascinating to see how Lovren and Matip or even Ragnar Klavan, handle him.

Like last week's London derby, this is another Big Six clash whose importance is magnified by the transfer window still being open – even if both clubs have shown a similar reluctance to use it.

Indeed, Arsene Wenger has been employing even more makeshift central defences than Klopp.

And while Wenger seems certain to become the butt of Gooner ire should Arsenal stumble to a second away defeat in a row, Klopp himself would not escape criticism if he does nothing about his main weakness.

From this vantage point, it seems that Liverpool would not be caving in if they took £140m for a player that cost them £12m, and would be stronger overall if they were to buy Van Dijk with half of it.