Over the weekend, the Sunday Times reported that a doctor who prescribed performance-enhancing drugs for athletes claimed to have worked with footballers from clubs including Leicester City.

On Sunday afternoon, Leicester beat Southampton to go seven points clear at the top of the Premier League. On the same day last year, Leicester were seven points adrift of safety at the bottom of the table. In that calendar year, Leicester have taken 91 league points – 18 more than the next best teams, Arsenal and Tottenham.

In most other sports, such an improvement would lead to dark mutterings and sceptical questions, if not open derision. In the post-Armstrong world, no evidence is even necessary – the improvement alone is enough to trigger the rumours.

In football, most people are still talking about a fairytale, even on the day when Leicester’s name was mentioned in connection with doping allegations. The world’s biggest sport is still the only one where doping doesn’t really feature in the conversation.

Lax anti-doping system

Football is an intensely competitive sport that offers huge financial rewards and is policed by a comparatively lax anti-doping system. The incentives that drive athletes in other sports to take drugs are all present, so why do people recoil at the idea that a lot of top footballers are probably doping?

Part of it has to do with the still-common idea that performance-enhancing drugs don’t help you to play football. Their benefits are more obvious in a sport like cycling, which is all about athleticism and endurance, than in football, where the technical and tactical components are more important than the physical.

That argument is obviously absurd. Performance-enhancing drugs can’t turn you into a good footballer, but they can help turn you into a better one. Other things being equal, players who can improve strength, speed and stamina will become better.

Another argument is that contracted players usually have a guaranteed minimum income. The risks of exposure therefore outweigh the possible rewards doping can provide. But this doesn’t address the fact that a doped footballer might have more chance of winning a lucrative contract in the first place.

Still another argument suggests that the highly social nature of the sport, where teams consist of large numbers of players who are frequently on the move, and are in the glare of intense media interest, makes it hard to preserve the sort of omerta that dopers usually find indispensable.

But while those factors might make it complicated for a football club to dope in an organised way, it doesn’t prevent individual players from consulting privately with unscrupulous doctors to find a personal doping solution.

In that case the people most likely to catch them in the act are probably not the anti-doping agencies, but their own employers.

Football clubs in Germany at least have upped their scientific game in recent years, as I discovered when speaking to Dr Markus de Marées and Dr Pamela Wicker at the German Sports University in Cologne in September 2014.

Dr de Marées, of the Institute of Training Science and Sport Informatics, told me that Bundesliga clubs test their players’ blood “very often. Three to five years ago they did it three or four times a year. Now they’re doing it nearly every day.”

A club running frequent blood tests on its players could soon be aware of any freelance doping being undertaken. But what action are they likely to take?

Few doping positives

When I asked Drs Wicker and de Marées why there are so few doping positives in football, Dr Wicker, of the Institute of Sports Economics, answered flatly: “Because Fifa doesn’t want any positive tests.”

Dr de Marèes: “Doping will always be found in sports where you can earn lots of money. But in football it’s like they don’t want to have it. Maybe they’re looking at the wrong parameters. Maybe they’re looking at the wrong time. Or . . . maybe the players are clean. I don’t know. I used to sit in front of the TV cheering for Jan Ullrich. I was definitely sure that he didn’t dope. I was naive enough to think that. Now it’s gone totally in the other direction. I don’t believe that high performance sports are free of doping.”

Dr Wicker referred to the Operacion Puerto trial. “We had that Fuentes case with the cyclists in Spain. They also had some blood samples from other athletes, apparently including football players. And . . . I’m still wondering why they did not pursue these cases. Because the cyclists, they were caught, and the others, they were just put in the bin. It’s a question mark, I think. It gave a bit of an indication that the people in charge in Spain said: you can touch these cyclists, but not our great football players.”

Dr Wicker was wrong about one thing: those blood bags are not in the bin . We’re waiting for a final verdict on the appeal against the judge’s decision to destroy the bags. The eventual verdict will have a great bearing on whether football’s mood of passive denial can go on for much longer.