Manchester City's title defence has not started according to plan, with the champions already trailing Liverpool by eight points.
Jurgen Klopp's side have won eight from eight in the Premier League, while City headed into the international break on the back of a surprise home defeat to Wolves.
For Pep Guardiola, City's defence has to be a huge concern, even though the former Barcelona boss has insisted the club will not be looking to replace the injured Aymeric Laporte in January.
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Laporte is set to miss the majority of the season after sustaining an Anterior Cruciate Ligament injury in August, while Vincent Kompany has left a sizeable void in City's defence.
Nicolas Otamendi has been largely unconvincing, while John Stones has his own injury problems and Fernandinho – arguably the Premier League's best defensive midfielder – has had to fill in at the back.
Ahead of Saturday's trip to Selhurst Park to face Crystal Palace, we use Opta data to assess how Guardiola can patch up City's struggling defence.
RELIANCE ON OTAMENDI A CAUSE FOR CONCERN
Guardiola has not been helped by a spate of bad luck with injuries, especially with Laporte, who has been mightily impressive since his arrival from Athletic Bilbao in January 2018.
Stones, meanwhile, has been in and out of the side due to both injuries and form, with Kompany preferred for the run-in last season. Otamendi looked set to join Kompany in leaving the club in the off season, though has been a mainstay of City's back line, making seven league appearances and two more in the Champions League.
The Argentine does boast a passing accuracy of 92.52 per cent, which is higher than Fernandinho or Laporte, while he has also lost possession 148 times fewer than the Frenchman.
While Otamendi has only featured in 25 Premier League matches since the start of last season, he does have a higher tackle, duel and aerial duel success rate than Laporte and only conceded 16 fouls.
However, the former Valencia man showed clear weaknesses in the defeat to Wolves, recklessly lunging in on Raul Jimenez in the build-up to the opener, while it was his mistake at Carrow Road which led to Norwich City's third goal in a 3-2 win for the Canaries.
Of the players who have played at the back for City since the start of 2018-19, only Otamendi (2) has made errors which directly resulted in a goal.
KOMPANY'S IMPACT UNDERESTIMATED?
City reportedly moved for Harry Maguire in the off season, only to baulk at Leicester City's asking price, which was eventually paid by cross-city rivals Manchester United.
However, the decision not to replace inspirational former captain Kompany, who scored a stunning goal against Leicester as he led City to the title last term, seemed a risky one.
City did not lose a single game in all competitions last season in which Kompany started, with the Belgian having been named in 13 Premier League line ups.
Kompany played 1,223 minutes in the top flight last term, making no errors resulting in a shot at goal, while managing an impressive pass accuracy of 93.07% behind only Stones in terms of City's defenders.
The 33-year-old lost possession 93 times, though, perhaps due to a lack of pace, did concede 17 fouls – more than Otamendi or Stones despite playing fewer games.
He was dribbled past by an opponent on only one occasion and, from the 18 matches he started in all competitions last season, City claimed 17 wins, conceding just 12 goals.
SETTLE ON STONES UNTIL JANUARY
The simple answer to City's problems is likely to get Laporte back fit and firing as soon as possible, given they have an 82 per cent win percentage with the 25-year-old starting in the Premier League since the start of last season, compared to 75% without.
However, for now Guardiola must find a defensive pairing he can stick with until January. Fernandinho and Otamendi have featured in the last three league matches, but against Wolves their lack of pace was exposed.
Stones should soon return to action and, though the England international's form has been criticised, his statistics make for promising reading.
The former Everton man has a tackle success rate of 75%, higher than any of City's other centre-backs, and has conceded just six fouls since the start of 2018-19.
If Stones can stay fit, he should be City's first-choice centre-back until the new year, with Otamendi and Fernandinho vying for the other spot.