Frank Lampard pointed the finger at his forwards after the game. "If you don’t score you are always liable for a sucker punch and we got it," he told Sky Sports. But there is a growing suspicion that Chelsea are more likely to suffer stoppage-time goals like the one against Newcastle while Kepa Arrizabalaga remains their goalkeeper.
The unsuccessful attempt to parry Isaac Hayden's header wide of the post was no howler. Other goalkeepers make more spectacular mistakes. But it was the sort of incident that has become commonplace for Kepa and in goalkeeping circles, there are question marks over his technique - as former Premier League goalkeeper Richard Lee explains.
"It is not a mistake," Lee tells Sky Sports. "It is certainly not one that would go down as an error. If he saves it, it would go down as a very good save. However, I do think there are other goalkeepers in the Premier League who would have made the save from that header.
"If you look at the moment the header is made, his hands are just tucked inside ever so slightly. All it means is that it's just tougher to get the coordination right. You need to have such quick hands to get them into the position they need to be in.
"From close range like that, when it is a reaction save, you don't really need momentum to get a huge dive away. If anything, you want to have a solid position so that you can make a reaction save. His set position as the ball is headed isn't in the optimum position it should be in. He cannot get his hands where they need to be to get solid contact on the ball."
Lee, co-founder of Goalkeeping Intelligence, a learning resource for goalkeepers, first noticed this tendency in Kepa's very first game at Stamford Bridge in August 2018. His decision to swing his arms behind his back, seemingly in an effort to gain momentum, cost him valuable time when attempting to keep out Henrikh Mkhitaryan's low shot for Arsenal.
John Harrison, an educator for Goalkeeping Intelligence with an emphasis on statistical analysis, did not even have to wait that long to have concerns.
"I think the day after he signed they put out a tweet with a video of Kepa in Chelsea training and that's when I first noticed it," Harrison tells Sky Sports. "Since then I have been keeping an eye on how he has been doing and the types of goals that he has been conceding.
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"The two areas where Kepa really struggles are one-on-one situations and close-range headers. One-on-ones are a common thing for young goalkeepers to struggle with given that the majority of it is decision making - in other words, do you come and try to smother the ball and tackle the striker or do you hold your ground.
"But the close-range headed shots are where the arm-swing technique come in. A lot of Spanish and German goalkeepers seem to position their arms behind their body in order to swing them out in front of them when the ball arrives.
"For long-range shots, this isn't an issue as there's time to get your arms in position to save the ball. But for close-range shots this often means that your arms are not in position to save the ball as it goes past you."
There are some alarming statistics that support this view of Kepa's ability.
A save percentage of 74 per cent from shots outside the box is far from impressive but it is at least better than Ederson's record for Manchester City. However, it's Kepa's save percentage from shots inside the box that is extraordinary. He is keeping out only 51 per cent of those shots. That's far worse than any other regular Premier League goalkeeper.
Save percentages can be unreliable metrics because they treat all shots as equal but expected goals models correct for this - putting a value on the likelihood that every shot finds its way beyond the goalkeeper based on its type and location. Post-shot data can also reveal the likelihood of a save being made based on where on the target it was struck.
Here too, the record of the man who remains the most expensive goalkeeper in history indicates that he is a hindrance rather than a help.
Indeed, the statistics from this season suggest that while the average goalkeeper would have conceded 22 goals from the shots that he has faced, Kepa has instead conceded 30.
That eight-goal performance deficit makes him the worst goalkeeper in the Premier League this season based on this metric.
In fact, it was a problem last season too. Since Kepa arrived in the Premier League he has cost Chelsea almost 10 goals more than would have been expected. David de Gea's struggles have been more high profile but even his record is better than that. The other four first-choice goalkeepers for last season's top six have all saved their teams goals overall.
That highlights the problem facing Chelsea - the feeling that their progress could be being undermined. Only Manchester City have faced fewer shots this season but no team in the top seven have conceded more goals. Crystal Palace have a better defensive record. Even Brighton, just three points above the drop zone, have conceded only one more.
Something is going wrong here but it might not be systemic. These statistics suggest that a change of goalkeeper could put a very different slant on Chelsea's season.
How concerned is Lampard? Publicly, as might be expected, he has backed his goalkeeper. When Kepa was caught out by Daniel Wass' cross-shot away to Valencia in November, the Chelsea boss acknowledged "there might be the feeling he pulled his hands away" but stopped short of blaming Kepa for the late equaliser.
However, reports emerged last month suggesting that Lampard was keen to replace Kepa in the summer. That would be quite a decision given Chelsea's investment in the goalkeeper - one whose peak is presumed to be ahead of him at the age of just 25.
But Chelsea need only look at how a change at the back has succeeded in transforming both Manchester City and Liverpool in recent seasons. While Kepa continues to cost Chelsea goals that other goalkeepers would keep out, expect his future to remain under scrutiny.