A WEEK that saw reports of widespread doping and cover-ups in Russian athletics inevitably prompted the question: how clean is football?

Arsene Wenger, possibly the most vocal high-profile manager on this subject, weighed in saying that in 30 years in the game he had “never injected my players to make them better” but that some of the opponents he had faced were not “in that frame of mind”. Cue the Football Association asking him to explain his comments and provide any further information he might have.

The problem with doping in football is that you can’t prove a negative. You can’t definitively prove there is no use of performance-enhancing drugs. Circumstantially, you can make a strong argument that it must exist. Other sports, from cycling to weightlifting to baseball and now athletics, were in denial for a long time, just as football seems to be now. Administrators at the top of cycling and athletics in particular were accused of being enablers, through being either incompetent or corrupt, which is how many see the folks who run Fifa and Uefa.

Players are fitter and stronger than they’ve ever been – watch footage from the 1980s and they’ll look like a different species. The financial stakes are as high as they’ve ever been and so, the thinking goes, surely some must be cheating?

Maybe they are. But there are also plenty of reasons to suggest they are not. First and foremost, as the number and type of tests have increased dramatically in the past decade, the positives have dried up. There was a rash of failed drug tests from the mid-1990s – when controls were stepped up – until about a decade ago. Since then, there has been nothing, at least in the top leagues.

It could mean, of course, that dopers have become particularly adept at doping and getting away with it and remain several steps ahead of the testers (who now have more resources than ever before). Of course, if that’s the case, you wonder why, for example, Russian athletics didn’t just use these widespread undetectable doping techniques that football supposedly uses, rather than going through the trouble of destroying samples, as they are alleged to have done.

Maybe it’s because there is no such thing as totally undetectable performance-enhancing doping.

Another factor is that footballers are tested and dissected like never before by their own clubs and national FAs for player evaluation and sports science purposes. And since a lot of the testing is done by measuring shifts in baseline haematological values – that’s the premise of the so-called “biological passport” which is being introduced into football – clubs know full well when something fishy has gone on.

What’s more, so do national teams and, crucially, whenever a player moves to another club, so too does a footballer’s new employer. This means you have multiple stakeholders with access to an athlete’s medical records – something that doesn’t happen in individual sports. This makes it a lot more difficult to keep doping secret. A footballer who dopes with, say, his club, will be found out by his national team or by the next club he joins.

There is a physical and medical argument as well. The types of doping that are generally guaranteed to increase performance on the day – usually synthetic stimulants of the kind that were used before drug testing – are extremely dangerous and easily detected. Doping that increases stamina by improving the flow of oxygen through the blood – nandrolone and its derivatives – is precisely what gets tracked via the biological passport.

Steroidal doping aimed at increasing strength and muscle mass only yields results when athletes train for extended periods, something which footballers – unlike, say, sprinters, swimmers or weightlifters – do not do. If you do four 90-minute sessions a week in-season, that’s already a lot in football terms.

Most of all, there’s the fact that there’s no “noise” around doping in football. Up until a decade ago, there were were plenty of rumours and accusations and many were later vindicated. Today, there’s tumbleweed. Which, again, may speak to a gigantic level of “omerta” in the game or it may simply mean there isn’t much going on.

The last major rumour surrounding a club involved Real Sociedad. Inaki Badiola, a former president, revealed that his predecessors had used a slush fund to purchase illegal and controlled substances. The team jumped from 13th to second in La Liga in 2002-03. The following season, the manager, Raynald Denoueix, was sacked. He never again worked in football.

Beyond that, what you have is vague accusations from convicted dopers in cycling alleging that they saw footballers frequent their clinics. (They could recognise them as footballers but, curiously, have stopped short of naming them). You have Eufemiano Fuentes, the doping doctor at the heart of Spain’s Operation Puerto scandal, saying he worked with footballers but – again – not naming names. And you have 211 blood samples found in Fuentes’ offices that were destroyed at the end of the trial, without anyone ascertaining who they belonged to or whether there was evidence of doping.

Beyond that, there’s nothing. Which, again, suggests football, even as scrutiny becomes greater than ever, has either become much better at keeping a secret or, really, there’s nothing there.

Sometimes a cigar is just a cigar. Football has a raft of problems. There is very scant evidence that, right now at least, performance-enhancing drugs are among them.

MARTIN O’Neill and the Republic of Ireland host Bosnia tomorrow in the return leg of their Euro 2016 play-off. If you wanted drama and edge-of-the-seat tension, both teams delivered it on Friday night, with the added meteorological twist of a dense pea-soup fog enveloping the pitch in Zenica and contributing to a surreal atmosphere.

Ireland, severely depleted by the suspensions of Jonathan Walters and John O’Shea and the injury to Shane Long, raised the barricades and hung on for dear life for much of the game. You can’t fault O’Neill for doing that and he was rewarded when Robbie Brady emerged from the mist to give them a late lead against the run of play, even if it did only last a few minutes, until Edin Dzeko’s equaliser.

Tomorrow’s return leg ought to throw up much of the same. For the neutral, it’s wonderful and in stark contrast to the empty inanity of the so-called prestige friendlies that littered this international weekend.