Wayne Rooney has not been struggling for a few days, or a few weeks, or even a few months.
The Manchester United striker's decline can be traced much further back, all the way to the day Alex Ferguson left Old Trafford, if not before.
He has been fading for more than two years. It is not a run of poor form. It goes much, much deeper than that.
The easiest way to explain what has happened to Rooney is to point out that he is not the same athlete he was, to blame nothing more than the passing of time.
There is some merit to this. He is, after all, 30. Rooney started out at 16. A decade and a half at the top takes its toll.
Far more significant, far more damaging, though, are the managers who United appointed to replace Ferguson.
Neither David Moyes nor Louis van Gaal have shone in the role, but both have proved calamitous for the England captain.
When Rooney is at his best, it all comes naturally. The problem over the past two years is that Moyes and van Gaal have tried to change that. They have tried to fill his head with instructions and plans. They have tried, in short, to make him think. It was meant to make him a more complete player. Instead, it has served only to blunt his edge.
Rooney has often been described as the last of the "street footballers".
He is the final standard-bearer of a generation who knew life outside pristine academies. He honed his skills playing with his friends on the streets and in the parks of Croxteth. He plays almost exclusively on instinct.
It is not meant as an insult to say that he does not think about what he is doing. When Rooney is at his best, it all comes naturally.
The problem over the past two years is that Moyes and van Gaal have tried to change that.
They have tried to fill his head with instructions and plans. They have tried, in short, to make him think. It was meant to make him a more complete player. Instead, it has served only to blunt his edge.
There was a perfect example against Stoke City (on Saturday).
Late on, the ball fizzed across to Rooney just inside the box. The Rooney of old would have struck it first time. He had a clear sight and an easy strike on goal.
The new Rooney paused. He wanted a touch, to consider his next move.
He tried to cut inside, but took too long. He ended up stumbling over the ball. Rooney's instincts are lost in his thoughts.
In a more exciting side than van Gaal's United, that would not necessarily be an insurmountable problem. Rooney's team-mates could make his mind up for him.
If he saw a winger flying down the flank, or a midfielder bursting beyond him, he would not have to think; the correct decision would be there, obvious, visible.
Under van Gaal, though, this does not happen. Rooney is not in a framework designed to get the best out of him.
All of United's players are too slow, too ponderous.
Rooney has, in a sense, suffered a double blow.
Not only have his managers tried to change him into something that does not suit him, but they have also turned his team into a place where he does not belong.
In another world, Rooney might have started at Old Trafford yesterday wearing the blue of Chelsea.
It would be easy to say he would have been better off. Maybe he would, had Jose Mourinho been able to coax the best out of him.
Maybe then he would not be in a position where there must be a question mark over his role with England this summer.
Never mind whether he gets into the team. There are doubts about whether he gets into the squad.
THE TIMES, LONDON