Chelsea have suffered back-to-back defeats with Thomas Tuchel caught in two minds about how to use Romelu Lukaku.
The football world looked on in fear after the Champions League winners added Lukaku and Saul Niguez over the summer while offloading a host of younger players.
For those not paying close attention, four wins since the last international break might represent the west Londoners’ consistency and power, but those watching closely could see problems emerging.
Chelsea have not put in a complete performance this side of that September break, winning matches through dogged defending, clinical finishing and masterful substitutions.
Their last two matches in particular have shown that brilliant tacticians in Pep Guardiola and Massimiliano Allegri are able to exploit those chinks in Chelsea's armour.
Having won the Champions League last term, Chelsea rightly went into this season's tournament as one of the favourites. The additions of Lukaku and Saul should have made Chelsea stronger but, in truth, they have temporarily weakened the team structure.
With Saul having struggled badly in his first two matches, he has dropped below Ruben Loftus-Cheek and possibly even Ross Barkley in the midfield pecking order.
The two England internationals were brought on ahead of the big-name, new loan signing from Atletico Madrid in the second half of Chelsea’s 1-0 defeat to Juventus on Wednesday night.
Yet, it is Lukaku's situation that poses a bigger question for Tuchel. The £97.5 million ($138m) striker signed from Inter has found himself isolated in recent weeks, and has been doing his level best to make the most of the scraps he has been given.
Impressively, he netted two goals from just two shots against Aston Villa earlier in the month. He followed that by spending 90 minutes patiently waiting for service in the No.9 position against Zenit, eventually scoring the winner from a deep Cesar Azpilicueta cross.
But in the last four games, Lukaku has not scored. Partly, it is down to his team-mates not linking up with him well enough. Since Mason Mount dropped out of the team injured, the other candidates at No.10 and the forwards have been unable to strike up a working relationship on the field.
Furthermore, the wing-backs are rarely supplying the kind of balls to help him take advantage of his physical gifts.
It has led Chelsea to an existential question about the tactics that served Tuchel so well towards the end of last season. Perhaps to get the best out of their club-record signing, they need to commit more to playing to his strengths.
There was an experiment in playing a new 3-5-2 formation at home to Manchester City last weekend, the shape used by Antonio Conte at Inter last season. Timo Werner partnered Lukaku up front and the Blues' intense pressing system was abandoned in favour of a counterattacking game with a low block.
Although it may suit Lukaku, it did not suit the rest of the squad, who returned to their usual 3-4-3, possession-based and counter-pressing style in Turin.
But that did not work either. Having found himself on the fringes of the match again, when a chance finally fell to Lukaku in the 83rd minute, he uncharacteristically blazed over.
"We had a day off [after Man City] and two very good training sessions yesterday," Tuchel told reporters after the match. "We were absolutely sharp, looked very fresh and very hungry, and ready for a bounce back.
"It’s very difficult to put on a huge rhythm against a team who defends so deep. If we defended deep against City it was difficult for them to create chances. It was the same for us here.
“But the difference was we gave two big chances and gave the belief back into the stadium."
Of course, the defeat in the Champions League does not matter much with two matches against Malmo to come next. However, Juventus are considered inferior to what they once were, having lost Cristiano Ronaldo to Manchester United and not kept a Serie A clean sheet in 20 matches.
Tuchel will have seen these defeats coming earlier than most through his habit of looking at performances and not results, and it is clear that Chelsea have everything needed to build on the glory of last season with further incredible victories.
The biggest factor in doing so will be whether Tuchel can tweak last season's recipe to integrate Lukaku, or if he needs to scrap much of his old tactical set-up.
