For the second successive season, the Anfield cameras could be trained on Alexis Sanchez.
In March, the Arsenal star was surprisingly demoted to the bench for a demoralising defeat. This month, he could be recalled - a man who eyed the exit, now charged with restoring Arsenal's winning ways.
The fit-again Chilean scored 24 league goals and recorded 10 assists last season. He might be the Premier League's outstanding individual and he may be capable of finding space behind Liverpool's overlapping full-backs.
But, even on his first appearance of the campaign and perhaps even his last for Arsenal, this is about far more than Sanchez or his Anfield counterpart, the ill and unsettled Philippe Coutinho.
The reality is that Liverpool pipped Arsenal to fourth place by one point while taking six off them last season. They scored seven goals against Arsene Wenger's team, four of them in 18 blistering minutes in London, and the inquests about why Arsenal lost their record of top-four finishes under the Frenchman could begin there.
Arsenal need to combat Liverpool's pace and intensity, to show similar energy and coherence.
The problems are not confined to just facing the Reds - Jurgen Klopp's big-game specialists went unbeaten against all of last season's top seven - but the Gunners' issues are particularly acute. They have encountered troubles on their travels in the last nine months, culminating in last Saturday's loss at Stoke.
Arsenal were luckless then, but they cannot allow that to become a theme.
This promises to be a high-scoring affair. It is a meeting of the two most porous defences in last year's top six. It will be instructive if Klopp still trusts the erratic left-back Alberto Moreno, who produced an error-strewn display against Arsenal last August, but Wenger's rearguard may be under greater scrutiny.
His back three have struggled of late, with the suspicion that Nacho Monreal has been miscast in the middle of the trio, while Liverpool fired a warning on Wednesday.
Hoffenheim arrived at Anfield with three central defenders and had to change system with three-quarters of the game remaining and after three Liverpool goals.
Klopp's potent inverted wingers wreaked havoc. A particular responsibility lies with whoever is Sadio Mane's immediate opponent. The speedy Senegalese scored home and away against Arsenal last season. Under Klopp, Liverpool have tended to be quick starters, to both games and seasons. Sometimes Wenger's Arsenal have been too slow off the blocks in both respects.
As defeat tomorrow could leave Arsenal six points behind Manchester United, they risk finding themselves playing catch-up again.
Yet a first win at Anfield since 2012 would effect a swift reversal in the balance of power between possible rivals for fourth place again.
But this time Wenger should realise Sanchez is his likeliest match-winner.
LIVERPOOL V ARSENAL
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