The intense spotlight that has been trained on one global Liverpool icon switched to another on Anfield's most recent desperate night.
Mohamed Salah has come under fire for his poor form this campaign - and was consigned to the bench for the second successive Premier League game as the Black Cats visited on Wednesday.
But it was skipper Virgil van Dijk, a unmatched defensive foundation as Liverpool have collected the array of major prizes, whose poor form came under the microscope during the 1-1 draw.
Van Dijk, 34, and Salah, 33, both signed new lucrative two-year deals in the summer, with not one Liverpool eyebrow raised at the prospect of securing the futures to a seasoned pair much nearer to the end of their careers than the start.
In fact, it was a cause of celebration - but now there is no escaping the harsh truth that standards have dropped worryingly for both.
Liverpool have been exposed in defence ever since head coach Arne Slot and the club's transfer committee undertook a £450m summer rebuild that has not yet shown anything like value for money.
At the same time, Van Dijk has started to lose the sense of being untouchable he has carried since his £75m transfer from Southampton in January 2018.
Van Dijk has not been helped by center-back colleague Ibrahima Konate's dramatic dip, along with Milos Kerkez not finding his feet at left-back. But the esteemed defender has also had significant difficulties, as demonstrated by his panic-stricken handball that conceded a penalty in the heavyweight Champions League loss to PSV Eindhoven at Anfield.
It was captured in the 67th minute on Wednesday when Chemsdine Talbi gave Sunderland a well-earned lead, Van Dijk giving the ball away before standing off and turning his back on a 25-yard shot that struck him and looped out of the reach of goalkeeper Alisson.
For a defender of such unquestionable quality, Van Dijk has an peculiar tendency of turning his back on the ball, sometimes to Liverpool's detriment.
Bad luck at the conclusion, yes, but it was a situation Van Dijk courted with his unusual failure to take charge, Sunderland's Talbi capitalising.
"Van Dijk loses the ball and then he just drops off. 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 was faultless. Every game he was imperious, but right now he's slipping up and hesitating."
As with Salah, a player of Van Dijk's stature must not be dismissed after winning two Premier Leagues, the Champions League, the FA Cup and two EFL Cups in a illustrious Liverpool career.
He has, though, looked a pale imitation of his usual commanding presence 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 exclusive domain alone in a Liverpool team packed with experience, it was missing here. No-one was motivating a team that once again looked bewildered to grab the game by the initiative.
Van Dijk's poor display, which ended with him being used as the desperate measure of acting as an emergency striker, was symptomatic of a distinctly poor Liverpool performance - which made Sunday's win at West Ham seem like the outlier rather than the norm.
Slot persisted with the side that stopped a run of nine losses in 12 games at London Stadium, Salah once more starting on the sidelines.
The Egyptian was introduced at the start of the second half as the Kop turned to him for inspiration. It was not forthcoming, with £125m Alexander Isak also anonymous after getting off the mark with his first league goal for Liverpool on Sunday.
Slot would have been under increased scrutiny had Florian Wirtz's 81st-minute shot not deflected in off Nordi Mukiele to set up what Liverpool hoped would be a grandstand finish.
A late scare came - but at the other end. Liverpool were only spared embarrassment 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 dribbled past keeper Alisson.
Slot and his fading champions ultimately had to accept the point knowing it could have been worse, with Alisson fortunate 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 sluggish, labored and devoid of creativity. Even the traditional late rally after the equaliser carried scant belief. Displays like this are the reason their attempt to retain the title has crumbled.
But full acknowledgment for the Reds' struggles on Wednesday must be given to Sunderland, who are being seeing the results for a summer of notable ambition in the transfer market, coupled with the excellent coaching of Regis le Bris.
The Black Cats were positive, self-believing and threatening.
Sunderland are now sixth in the Premier League with 23 points. It is telling 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 back to the drawing board.
Award-winning journalist specializing in digital media and communications with over a decade of experience in Canadian newsrooms.