Liverpool's tense 2-1 victory against Burnley might have secured three points, but it still raised doubts over their performances against sides from the bottom half of the Premier League.
It's been a feature of the season. All five league defeats so far have come against teams with at least one eye on the relegation battle, while Liverpool are still unbeaten against the elite. It's a peculiar condition that has kept experts guessing as to the reasons why.
On Sunday, even a fortuitous equaliser from Georginio Wijnaldum right on half-time never really settled the home team's nerves, and Liverpool still looked all at sea against a side that have won two away points all season.
After an hour it all became too much for Jurgen Klopp, and he hauled off Philippe Coutinho, replacing him with 17-year-old Ben Woodburn. Liverpool's winner from Emre Can followed one minute later.
That was coincidental, though some felt that the Reds finally having eleven players on the pitch gave them a better chance of winning: Coutinho had been dreadful and his ESPN FC rating of 3/10 was generous.
One theory about Liverpool's struggles has centred on an inability to break down packed defences, although Leicester's recent 3-1 win, achieved by taking the game to Liverpool rather than sitting back, poured some scorn on that notion.
Yet the poor form of Coutinho, added to a clutch of games he missed while recovering from injury, certainly lends credence to the original theory.
By November, Liverpool had not suffered unduly against teams sitting back. There was one poor performance -- a 2-0 defeat at Burnley -- but they then scored a combined 15 goals against Leicester, Hull and Watford. Coutinho was in superb form, scoring three times in those games and coming close on other occasions.
After he was injured, the side depended upon Sadio Mane, but once he'd left for a month of international duty, the wheels really came off. Football clubs in transition must always have their best players available and in good form, otherwise they'll fall victim to inconsistency.
Klopp's squad is generally weak and became transparently so since the turn of the year. Liverpool winning 43 points in the first half of the season was a minor miracle in itself.
Indeed a lack of real alternatives led to the possibility of Coutinho coming back from injury too quickly, and since he returned on Jan. 11, he has fallen way short of his best.
Some of his performances have not been a big surprise, since he's always had a tendency to have the occasional bad game. Even under Brendan Rodgers in the title chase of 2014, there were some days you just knew it wasn't happening for him.
Like Klopp on Sunday, back then Rodgers would often substitute the attacking midfielder, but by the start of 2015-16, it felt like Coutinho was being given longer to work his magic. Rodgers was rewarded with a late winner against Stoke in Liverpool's opening game, but that was a rarity. After 20 minutes or so, you can usually tell which Coutinho has turned up.
On a number of occasions this season the same could be said of the entire team, and it is true that the one time Liverpool switched on in the middle of a game rather than from the start, Coutinho was integral to an excellent 4-3 win at Arsenal, which also happened to be the opening game of a campaign.
Klopp's frustrations on Sunday were compounded by the fact his bench options were weak. He would not ordinarily want Woodburn on the pitch unless the game was already decided and there were seconds left on the clock, but with the score at 1-1 after an hour, the manager simply had no choice but to withdraw the struggling Coutinho.
So what happens next? In truth, given Liverpool's weak squad that is debilitated further by numerous injuries, there's no alternative to selecting Coutinho and hoping he finds his best form.
The 24-year-old has been at Anfield for four years, and though often linked with a move to Paris Saint-Germain or even Barcelona, he has never shown the consistency of Eden Hazard, for example.
Liverpool's various crises of 2017 certainly haven't helped, but perhaps estimations of Coutinho's talent need to be adjusted.
This is a player who augments any team with other gifted players, such as during that 2013-14 title challenge when he had Luis Suarez, Daniel Sturridge and Raheem Sterling alongside. But he will never be the star of the show.
Klopp speaks of adding new talent in the summer. Fans will hope Coutinho is there to take full advantage of that, because despite his limitations, he can still be a tremendous asset.