Random testing of AFL players ordered by the Australian Sports Anti-Doping Authority is less common in 2015, than it was. Adopting a more calculated "who, when and what" approach, ASADA is now more likely to hone in on footballers it suspects of engaging in suspicious activity.

For more than a decade, Justin Charles was the lone AFL footballer known to have tested positive to a banned performance-enhancing drug before Ahmed Saad was banned for 18 months, in November 2013, for ingesting a stimulant prohibited on match day in a protein drink.

Without any positive tests, ASADA issued a record 34 show-cause notices last June over Essendon's now infamous 2012 injection regimen. ASADA's CEO, Ben McDevitt, is adamant this involved players receiving banned drugs despite the fact that an AFL anti-doping tribunal declared the players not guilty this week.

In the past fortnight it has also emerged that Fremantle's Ryan Crowley tested positive to a banned substance on match day last season. Then came the news that Collingwood footballers Lachie Keeffe and Josh Thomas have tested positive to clenbuterol and, like Crowley, are staring down the barrel of lengthy bans.

McDevitt, in an interview with Fairfax Media this week, said the relative flurry of AFL positives was due to his agency becoming wiser about the activity of  players.

"I don't think we're particularly testing AFL players more, across the board we are actually reducing our testing numbers. But our testing is much more targeted," McDevitt said.

"Our testing is now much more intelligence-based, so there's a lot less random testing involved and this is the whole science.

"Testing is still a critically important tool. But what we need to do with intelligence is identify who to test, when to test, and for what substance to test. That's how you get better outcomes from testing."

Asked if Collingwood players Keeffe and Thomas, had been target tested by ASADA, McDevitt said: "I can't comment on that."

A former Australian Federal Police assistant commissioner, McDevitt announced himself as the tough-talking new boss of ASADA when took over from Aurora Andruska in the middle of last year.

Taxpayer-funded ASADA has never been more heavily scrutinised — or criticised — since it was announced publicly, in February 2013, that it was probing Australia's richest and most popular sports codes, the AFL and NRL.

Interestingly, McDevitt told Fairfax this week his discussions with AFL boss Gillon McLachlan, who took over from Andrew Demetriou last June, were "quite regular".

"We obviously have differing views on things, but I don't have any particularly issue," he expanded.

Asked what the pair's differing views have concerned, McDevitt said: "Just on processes and responsibilities and those sorts of things. Where the focus should be."

This week McLachlan publicly urged ASADA not to appeal against the finding that cleared 34 current and ex-Essendon players from banned drug use. McDevitt said in a media conference the day after the verdict that the CEO's statement would have no influence on his decision: "This is not a decision for Gil McLachlan."

He elaborated later in an interview with Fairfax: "I need to make the decision and we need to think about it really, really carefully. It's not a matter of saying 'everything's done here, move on folks, nothing to see here.' "

McDevitt added: "My sense is we're still only part way through the journey."

ASADA has a 21-day window to decide whether it will appeal the AFL anti-doping tribunal's not-guilty judgment of the players. McDevitt was surprised not to receive the tribunal's verdict on Stephen Dank, who designed and oversaw the supplements program at Essendon, on the same day and sees this as crucial information as ASADA weighs up the appeal option.

McDevitt expects to receive that information after the Easter break. If ASADA does not appeal the verdict, the World Anti-Doping Agency has a further 21 days to determine whether it will appeal the ruling on the Essendon players in the Court of Arbitration for Sport.