The intense spotlight that has fallen upon one global Liverpool icon shifted to another on Anfield's most recent frustrating night.
Mohamed Salah has faced examination for his struggles this campaign - and was placed on the substitutes' bench for the second successive Premier League game as the Black Cats came to town on Wednesday.
But it was captain Virgil van Dijk, a exceptional defensive bedrock as Liverpool have secured the array of major trophies, whose dip in performance became the focus during the stalemate.
Van Dijk, 34, and Salah, 33, both inked new lucrative two-year deals in the summer, with scarcely a Liverpool eyebrow raised at the notion of securing the futures to a veteran duo much nearer to the end of their careers than the start.
Indeed, it was a reason for joy - but now there is no escaping the stark fact that standards have dropped concerningly for both.
Liverpool have been susceptible in defence ever since head coach Arne Slot and the club's recruitment team undertook a £450m summer overhaul that has still to demonstrate anything like a good return.
At the same time, Van Dijk has started to lose the air of invincibility he has carried since his £75m switch from Southampton in January 2018.
Van Dijk has faced additional challenges by defensive partner Ibrahima Konate's loss of form, along with Milos Kerkez not finding his feet at left-back. But the esteemed defender has also had significant difficulties, as proved by his rash handball that gave away a penalty in the heavy Champions League loss to PSV Eindhoven at Anfield.
It was captured in the 67th minute on Wednesday when Chemsdine Talbi gave Sunderland a merited lead, Van Dijk giving the ball away before retreating and turning away on a 25-yard shot that deflected off him and drifted out of the reach of goalkeeper Alisson.
For a defender of such proven caliber, Van Dijk has an curious trait of turning his back on the ball, sometimes to Liverpool's detriment.
Misfortune at the finale, yes, but it was a situation Van Dijk invited with his uncharacteristic failure to act decisively, Sunderland's Talbi capitalising.
"Van Dijk surrenders possession and then he just retreats. It's the wrong decision. He needs to go to the ball. Him not making the decision means that no one else knows what to do."
"Virgil Van Dijk last season couldn't make a mistake. Every game he was imperious, but right now he's making mistakes and second-guessing himself."
As with Salah, a player of Van Dijk's stature must not be written off after securing two Premier Leagues, the Champions League, the FA Cup and two EFL Cups in a stellar Liverpool career.
He has, though, looked a faded version of his usual dominant persona this season, with the lowest recovery numbers per game during his Liverpool career, while key defensive stats are also down on last season.
And, while leadership should not be Van Dijk's sole responsibility alone in a Liverpool team packed with experience, it was lacking here. No-one was motivating a team that once again looked lost to take control by the scruff of the neck.
Van Dijk's subpar showing, which ended with him being used as the emergency option of acting as an makeshift forward, was symptomatic of a horribly mediocre Liverpool performance - which made Sunday's win at West Ham seem like the anomaly rather than the rule.
Slot kept faith with the side that halted a run of nine losses in 12 games at London Stadium, Salah once more starting on the sidelines.
The Egyptian came on at the start of the second half as the Kop looked to him for inspiration. It failed to materialize, with £125m Alexander Isak also ineffective after opening his account with his first league goal for Liverpool on Sunday.
Slot would have been under greater pressure had Florian Wirtz's 81st-minute shot not deflected in off Nordi Mukiele to set up what Liverpool hoped would be a grandstand finish.
Late drama came - but at the other end. Liverpool were only avoided defeat in stoppage time when Federico Chiesa's excellent defensive sprint allowed him to turn Sunderland substitute Wilson Isidor's shot off the line after he had beaten keeper Alisson.
Slot and his fading champions ultimately had to take a point knowing it could have been worse, with Alisson blessed to turn Trai Hume's shot onto the bar in the first half before Omar Alderete headed against the post after the interval.
Liverpool were lethargic, unimaginative and lacking in ideas. Even the typical final push after the equaliser carried little conviction. Showings like this are the reason their defense of their crown has fallen apart.
But huge credit for the Reds' struggles on Wednesday must be given to Sunderland, who are being rewarded for a summer of serious ambition in the transfer market, coupled with the superb management of Regis le Bris.
The Black Cats were adventurous, confident and a genuine threat.
Sunderland are now sixth in the Premier League with 23 points. It is symptomatic of the manner in which they have grown into life in the Premier League that they will be unhappy they left Anfield without adding two more to their tally.
For Slot and Liverpool, it is time for reflection.
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