Chelsea were found severely lacking in their 3-0 defeat at Arsenal, but the one thing we never expected from Antonio Conte's side was lack of belief.
That psychological deficit, as exposed by Branislav Ivanovic post-match, is a major issue: and one which Conte has to address as a matter of urgency,
“We didn’t start the game in the way we wanted,” he said. “We didn’t believe in what we were doing at the beginning and we were punished.”
Blips are expected at this stage of a manager's tenure at Stamford Bridge: systems take time to bed-in.
But the given truth is managers come in on a high, and that players listen to them - at least to begin with.
That lack of belief in Conte's new system will be seen as a major issue: for a similar lack of belief is precisely what tends to see an end to most of the managers that eventually collect their P45 from Roman Abramovich.
Conte's is a system that requires energy, enthusiasm, and intelligence.
A flowing, pulsating thing that is not defined by any mere formation, but requires disciplined interplay all over the park.
As we saw from Italy at the Euros, it is almost a new form of total football.
The question that must be asked is why Ivanovic, and his teammates, would lack belief in such a proven winning formula?
In usual circumstances, one might imagine failure by the boss to adequately communicate his philosophies: though, given what we know about this master of motivation from no lesser men than Andrea Pirlo and Giorgio Chiellini, that seems unlikely.
That leaves an explanation far more troubling, and far more difficult to remedy: that, perhaps, this set of players simply aren't up to working a system so complex and demanding.
Is that lack of belief actually something quite alarming: a lack of belief not in the system, but in these individuals' own ability to make it work?
If that is the case, there are no quick fixes here - something which would be bad news indeed for Conte, who occupies the role of canary in a coal mine as his team gear up to a day in Hull at the weekend.
To make sure, it's not hell instead, he needs a quick fix of self belief.