Chelsea defender Thiago Silva endured a torrid start to life in the Premier League.
The Blues' stand-in captain saw West Brom score three goals in the first half.
The Brazilian was at fault for the second after he was caught dawdling on the ball.
It showed even the most decorated defenders are not immune to the brain fades.
Thiago Silva is spending five days a week in the classroom – filling the gaping holes in his grasp of the English language.
If anything during his first few training sessions has been lost in translation, the scale of the task at hand was laid bare within half an hour of his Premier League career.
The veteran Brazilian, 36, has been shipped in to add experience, presence and leadership to a backline that has hamstrung Chelsea’s progress under Frank Lampard.
Instead, during a catastrophic first-half at the Hawthorns, the stand-in captain showed even the most seasoned and decorated defenders are not immune to the brain fades which still infect this side.
The circus surrounding Kepa Arrizabalaga was only ever the most obvious symptom of a wider problem.
Chelsea’s visit here in 2017 capped a title-winning run built on defensive steel; this comedy of errors illustrated why their attacking threat will never be enough to unseat the very best.
First came Marcos Alonso’s awful header which helped create Callum Robinson’s early opener. Then, 20 minutes later, Thiago’s dallying and dreadful touch allowed West Brom to double their advantage.
The crowning calamity came moments later when Chelsea’s frailties from set pieces saw Kyle Bartley make it three.
For all their fighting spirit after the break, the cracks of that chaotic start could not be eradicated entirely.
West Brom had three shots on target and found the net with every one, Chelsea had made three errors leading directly to goals – as many as the entire 2019-20 season.
They have now shipped 42 away goals since Lampard took over, more than any other top-flight side and only once in Premier League history had Chelsea been 3-0 down earlier in a match.
Penny for the thoughts of Kepa as he froze on the visiting bench.
For all the Spaniard’s floundering and frailty, a goalkeeper is only as good as the protection he’s afforded.
Silva was brought in to fix some of those leaks and, in time, his know-how will benefit this developing squad.
The opening half-hour at the Hawthorns, however, put-paid to any hopes that the 36-year-old would be the silver-haired bullet Chelsea wanted.
At least Lampard knows Edouard Mendy will be made to work for the £22million they spent on him. Left back Ben Chilwell, another costly new signing, should help, too.
But if their defensive struggles persist in spite of all these new faces, Lampard will have to ponder another troubling question: is the personnel really the problem, or does he have a blind spot when it comes to building a backline?