Chelsea celebrated victory against Leeds United on Saturday thanks only to the ice-cold nerves of Jorginho and Antonio Rudiger's maverick penalty-winning interventions.
Now the dust has settled, though, there will be cause for concern.
The Blues have conceded eights goals in their last three games; being 'horrible' to play against was the bedrock of the west Londoners' title charge having conceded just eight goals in their previous 18 games, but some concerning trends have emerged.
A solid defence will be needed to become champions of England, and better performances in that regard are required.
When analysing the Leeds game, Thomas Tuchel will have seen how no outfield player in his team completed more than 90 percent of their passes, how they were outrun by Marcelo Bielsa's side and how they lacked any kind of creativity.
Mistakes are becoming a habit, with the Blues having conceded four penalties in the league, which accounts for 36 percent of their goals against.
The Blues were without key players like N'Golo Kante, Mateo Kovacic, Ben Chilwell and Trevoh Chalobah, but Leeds had similar injury problems beforehand, as they were without key players Kalvin Phillips, Patrick Bamford, Rodrigo and Liam Cooper.
Of course, Kante is unique and adds to defensive qualities. Kovacic, like Jorginho, is one of three midfielders able to play consistently at the highest level, with Ruben Loftus-Cheek not yet ready for a starting role.
Italy international Jorginho is playing through the pain barrier just to keep his club afloat, with summer signing Saul Niguez not fully trusted by the Blues coach after a series of weak performances.
"My back is not in the best condition, but you need to push yourself more to help the team," Jorginho told BBC Sport after the match "That's what I needed to do. It's hard, but I pushed to help my team."
Additionally, Chilwell is the best left-sided defender at the club, with Marcos Alonso's strengths lying more in his attacking contributions.
Furthrmore, the Blues are shooting themselves in the foot with the contracts of Rudiger, Andreas Christensen, Cesar Azpilicueta and Thiago Silva all set to expire at the end of the season.
With particular uncertainty around Rudiger and Christensen, it leaves the squad at risk of losing players that have taken them to a second Champions League-winning season.
Madness ⚡🥶 #Hustle #AlwaysBelieve pic.twitter.com/8AoBC8W9nF— Antonio Rüdiger (@ToniRuediger) December 11, 2021
Notably, Denmark international Christensen, who is known for being mild-mannered and a top professional, has seen his recent performances dip.
Tuchel has publicly criticised him, amid turbulent negotiations, and would prefer to prevent him from leaving for free.
Meanwhile, Rudiger's performance against Leeds was not his best despite winning two penalties. His overall displays over the last 11 months have attracted interest from Real Madrid, Bayern Munich and Paris Saint-Germain, with the Spanish giants leading the race to sign him on a free transfer.
Rudiger would ideally stay, but he wants a salary that would see him earn a similar amount to his compatriots Timo Werner and Kai Havertz, who rank among the top-five earners at Chelsea.
The importance of Rudiger and Christensen has grown this season even as their contracts run down.
It is understood that Azpilicueta has been struggling to match the physical output that he has managed in recent seasons, with Tuchel often leaving him on the bench behind almost every other defender at the club.
One saving grace is that Chelsea have become more ruthless in front of goal this season, with the likes of Mason Mount scoring at a greater rate, and with match-winners being found from all areas of this large squad.
But even accounting for 17 different goal scorers this season, the Blues do not have a match-winner of the calibre of Liverpool forward Mohamed Salah.
Indeed, Liverpool and Manchester City have set the bar for success so high that Chelsea need to drag themselves back to their highest level.
Therefore, for a title charge, they will need to revive their defence. That defence was built on high-intensity football, great team spirit and a tactical structure that denied counterattacks at all costs.
"We don't have the moment where things go for us," Tuchel said on Saturday. "We don't have big things to adjust and the clean sheets will come when we focus on ourselves and not just the results."
That will still be Chelsea's formula for glory should they be able to regain that ruthless streak at the back.