Manchester City's three defeats in four games have shown that Pep Guardiola's side do have weaknesses. But where are they, and can they be solved?
Ricardo Pereira's late stunner gave Leicester all three points against Manchester City at the King Power Stadium, leaving them seven points behind Liverpool at the halfway stage of the Premier League season.
But are their issues short-term, and will Guardiola's frank assessment of his side's form help the camp in the long run?
Here, we look at three talking points from the Boxing Day defeat...
Can anyone replace Fernandinho?
At the base of midfield, City may have a problem. Though only a minor injury, Fernandinho's absence has highlighted a major concern.
John Stones was trialled in front of the defence in the 3-2 defeat by Crystal Palace, but started at centre-half on Boxing Day as Ilkay Gundogan was tasked with slowing down any dangerous transitions Leicester may attempt.
Although Gundogan has real quality, namely on the ball and in creating higher up the pitch, he just is not Fernandinho. Pep Guardiola said as much after the defeat.
"Fernandinho is not available to play so we have to overcome. Gundogan played good, he was good with the ball. We don't have this player like Fernandinho in this position, we have to think about it and solve it."
The Brazilian is a huge, yet understated, part of Guardiola's impact at City. Since Guardiola arrived in 2016, City have won 71.3 per cent of games with Fernandinho, and 59.3 per cent without him.
At 33, Fernandinho will not be starting week in, week out for long. For a team that have looked perfect in parts, suddenly there is a hole. This will no doubt be among the top priorities as Guardiola, Txiki Begiristain and Ferran Soriano sit down to talk January and beyond.
"We have to try to find a solution, I have to try to find the solutions," said Guradiola.
One player linked with filling Fernandinho's boots is Lyon's 21-year-old Frenchman Tanguy Ndombele. Athletic, competent on the ball and nowhere near his peak years, he could be the perfect replacement, and Guardiola should know; Ndombele was man of the match in the recent 2-2 draw with City.
Delph the weak link?
Granted, City's full-backs are rarely asked to defend, but when they are, Guardiola expects discipline in positioning and awareness.
Transforming Fabian Delph from a marauding midfielder into a left-back is one of Guardiola's greatest triumphs. It contributed to important victories midway through last season in the absence of Benjamin Mendy, but at Leicester he looked distinctly out of position.
City's full-back situation is unique, and you could forgive them for being unfamiliar with their surroundings in what some would call the traditional full-back position.
Of Delph's 190 touches against both Palace and Leicester, only 12 were in his defensive third. The overwhelming majority were in the opposition half, and Delph actually completed more passes in Leicester's half than any other City player.
Leicester's equaliser saw Delph flat-footed, on the half turn and nowhere near his man from Jamie Vardy's cross. His late red only capped off what had already been a disappointing display.
City host leaders Liverpool in a week, and Delph's likely replacement Oleksandr Zinchenko is another midfielder-turned-defender. Liverpool's front three may be licking their lips.
Guardiola keeping things honest
Despite a third defeat in four, Guardiola does not seem to be getting carried away. In his first season in England, this mini-crisis may have prompted fireworks in his post-match press conference.
In fact, the 4-2 defeat at the King Power two years ago this month led to the infamous "I am not a coach for tackles" line so often used against the Spaniard until he ran away with the Premier League with record points, goals and wins a year later.
But the last two defeats have been met with an honesty which will no doubt reverberate positively in the camp. Of late, all Guardiola seems to care about is getting the next victory, not making excuses or, perhaps more destructively, making it all about him.
He seemed disappointed yet calm and composed as he faced the cameras after the final whistle at Leicester, reiterating just how difficult it is to lead the Premier League, consistent with the line he pushed throughout City's dominance that it could all change soon.
"In September, October, colleagues of yours said that in January or February the Premier League is over. One month ago you said, 'OK there's Liverpool'. In football you are able to win a lot, lose a lot.
"Football is fascinating, unpredictable for many, many circumstances. That's why always you have to be humble, have to work and know every game is difficult, that's why what we have done last season, people say it's so easy, but I know how difficult it was."
And with Liverpool on the horizon, he recognised it would be a mistake to start thinking about them before the trip to Southampton.
"We have to start to think about Southampton. That is what we have to do."