McLachlan said it was time for the AFL to review not only its WADA-compliant performance-enhancing drugs policy, but also the competition's controversial "three-strikes" illicit drugs policy.

Appearing on Fox Footy's "On The Couch" on Monday night, McLachlan acknowledged that both the drug policies might need to be reviewed in light of recent events.

"We have had, I think, well-researched, well-considered policies and have had them in place for some time, both with illicit drugs and our ASADA-WADA policy," he said.

"We think we've had the right policy, we've got an integrity unit of 14 people.

"But I think, right now, if the policies aren't working then we need to look at them and have a look [at] what's going wrong because, after today, I think it's time to actually have a look at them."

McLachlan later added: "I don't want to jump to any conclusions or end points.

"This is a voluntary program, the illicit drugs testing policy, and we need to bring the players with us.

"But all I'll say is, if the policies and the settings aren't working, then we need to reconsider them."

It was revealed on Monday that Collingwood players Keeffe and Thomas had returned positive tests for the WADA-prohibited substance clenbuterol.

The two are provisionally suspended until "B" samples of their tests are examined and the ban in no way represents an admission of guilt.

The Collingwood bombshell landed on the eve of the landmark "innocent or guilty" verdict set to be handed down on Tuesday involving the 34 past and present Essendon players facing charges they were administered the banned substance thymosin beta-4.

Earlier this month, Fremantle midfielder Ryan Crowley tested positive to a banned substance that he said was in a painkiller he took for his sore back, and St Kilda forward Ahmed Saad was redrafted by the Saints in the off-season after serving an 18-month anti-doping suspension.

It was put to McLachlan on Monday night that the views about illicit drugs in the broader community had changed since the introduction of the AFL's "three strikes" illicit drugs policy — using the "ice" drug epidemic as an example — and that the competition's policy should evolve to keep pace with those changes.

McLachlan indicated that he agreed.

"This has been a voluntary program, but things have moved a long way since these policies were [put] in place," he said.

"And, I think, we acknowledge and accept that players have rights.

"But they've also got responsibilities, and if they are not going to deliver on those responsibilities, then I think we've got to address the settings."

McLachlan said he was shocked when he received the news about the two Collingwood players.

"I have to say, that one I didn't see coming, and it's incredibly disappointing and frustrating," he said.