Chelsea’s defence is under the spotlight following the heavy defeat at Manchester City.
The half-time hooking of a previously untouchable John Terry, bids being tabled for his potential replacement, and the sudden malfunctioning of Branislav Ivanovic, who has been the most reliable component of a well-oiled machine – it all seems to be going wrong at the back.
But the loss at City on Sunday highlighted another uncomfortable issue: the performance of Cesc Fabregas and the nagging question of whether he can rediscover the form which created such shivers of expectation a year ago.
Cast the mind back to that opening win at Burnley and how seamlessly the Spaniard fitted in.
He seemed the final piece of a perfect jigsaw. That pass to Andre Schurrle. The guile, touch and vision appeared miraculous as the Blues saw off all before them in the first half of the season.
Now, such is the ruthless way football never allows players to coast along on past glories, there must also be a debate about whether the brilliance of the early days that followed last summer’s transfer from Barcelona can be fully recaptured.
It was always a puzzle that Fabregas never quite managed to become the heir to Xavi at Barca he was expected to be when he left Arsenal to return to his boyhood club.
On the face of it, he had all the ingrained attributes to succeed, having learnt the Barca way at La Masia academy, even before setting foot in north London.
But the Catalan club did not identify him as the man they needed – and perhaps we are starting to see why.
Fabregas has never been blessed with great pace but now it is starting to be magnified as passages of play pass him by.
He can be more easily turned or brushed aside. Play does not always flow through him as it once did.
Dare we say, he has days when he looks lightweight and has faded since the turn of the year.
He still possesses that deft touch and can still angle a sweet pass to Eden Hazard or Diego Costa. But his power to control a match – bend it to his will – is not seen as often as when he was in his pomp at Arsenal – or Chelsea.
At times he appears a less effective version of Juan Mata, who Jose Mourinho discarded.
Part of the problem may be that Fabregas is caught between the famed Mourinho work ethic of tracking back or playing in the holding role and of being the creative fulcrum his team need.
Still only 28, he is far from old and surely has plenty left to offer. But Chelsea badly need him to be the old Cesc Fabregas again.