When he is streaming forward he is a force of football nature. It is hard to find a more uplifting sight than David Luiz. Chelsea's explosive Brazilian frequently makes the blood race. Such a pity, then, that from now on it will be impossible to forget that he can also make the stomach crawl.
You certainly needed iron entrails to avoid the condition when Luiz's young opponent and compatriot Rafael da Silva was sent off – quite legitimately according to the laws of the game – and he laughed in his self-gratulatory glee as he lay on the ground feigning injury.
The nausea quota for those who still like to attribute some basic sporting values to what goes on at the top of football these days could hardly have been higher.
There may, it is true, have been more outrageous cases of one professional conspiring in the dismissal of another from their workplace, but they were not so easy to recall.
One of them, no doubt, came in the second leg of the Champions League semi-final between Barcelona and Internazionale in 2010. Sergio Busquets, in glancing receipt of the arm thrown by Inter's Thiago Motta, went down in a writhing mass. The Nou Camp bayed for the red card which was duly flourished – but not before Busquets took a furtive peek at the referee through his narrowly parted fingers.
If Busquets' behaviour was despicable it did, however, have enough hint of shame to be furtive.
There was no such minor redemption in Luiz's behaviour when he needed the advice of a team-mate to stay down and perhaps contain to some small extent the degree of his pleasure.
When Luis Suarez provoked such widespread disgust by biting Luiz's team-mate Branislav Ivanovic his trade union, the Professional Footballers' Association, offered him advice on anger management. But what would be the most appropriate assistance in the case of Luiz and all those other pros who so frequently attempt to compromise their fellow workers?
Perhaps they could set up a seminar on the meaning of sport? Or enlist a few coaches of schoolboys to explain the devastating effect of the example set by the most influential figures in their lives? On the other hand, they might conclude that most of the damage has already been done, and irreparably so.
Maybe it was because the title had already been won but Rafael's manager Sir Alex Ferguson has rarely been so even-handed in reacting to a game and decision that had gone against his team. Certainly for once he flew by the post-game candour test. Yes, of course his player had to be sent off for aiming a kick at Luiz. He had been played for a sucker by the Chelsea player, who twice threw his arm at Rafael, but then Luiz's behaviour was outrageous too, adding: "The referee has been bought by the fact Luiz is rolling around like a dying swan – and that convinces the referee. He [Luiz] was smiling. That was bad. What kind of professional is that?"
There are many unflattering answers but none one of them includes the suggestion that Luiz is any nearer than a million miles to being unique.
Indeed, it is hard to know which is more endemic in football, the wholesale cheating or the selective morality that comes in its wake.
In the melee that followed Sunday's incident, Ryan Giggs was especially outraged by Oscar's waving of an imaginary card in the face of referee Howard Webb. Giggs's body language said that he had seen something quite revolting, certainly a grievous offence against something that might pass for a professional's code.
Presumably he had forgotten that in one of the most controversial dismissals of last season, when Manchester City's Vincent Kompany was sent off for a tackle on Nani, Wayne Rooney had run yelling into the face of referee Chris Foy demanding a red card.
City manager Roberto Mancini said: "Rooney told the referee his decision." Ferguson responded equably enough. He said: "I can understand where Roberto is coming from because that's what happens with players today. They all appeal for penalties and players to get sent off – it's an unfortunate part of the game."
On Sunday, Chelsea interim manager Rafa Benitez said he hadn't seen the collision but in any event he did not comment on such incidents. "You can talk the day after such incidents," he said, "but nothing changes."
What is done is done, said Rafa, and what could you do but move on?
Maybe, once in a while, you might say that something is so bad, so wretchedly at variance with what most people would deem decent behaviour, in the street let alone a sports field, that it demands something more than a shrug of the shoulders.
You might push David Luiz into a corner – something which admittedly would require a little nerve of its own given his defiant demeanour towards Webb – and say that what he did shamed the instincts of every professional footballer still in possession of a set of working values.
You might even tell a player-statesman of Ryan Giggs's prestige that it serves no one any good when you reserve all your indignation for only those occasions which work against the best interests of your own team.
There was, certainly, little difficulty in identifying the big loser when David Luiz, a player who some time ago announced levels of wonderful accomplishment, lay on the ground shamelessly rejoicing in his sharply deceitful practice.
It was football, the game increasingly bedevilled by full-blown fakery.