• What is clenbuterol?
• Who are Lachie Keeffe and Josh Thomas?

IT MAY be time to reconsider the League’s drug policies, AFL boss Gillon McLachlan says.

McLachlan described Monday's news of Collingwood pair Josh Thomas and Lachlan Keeffe returning positive samples for performance-enhancing drug clenbuterol as "incredibly disappointing" and said the policies needed to be revisited.

His comments come less than 24 hours before the verdict is handed down in the ongoing case involving Essendon and ASADA that has now stretched beyond two years.

Speaking on Fox Footy's On The Couch, McLachlan said both performance-enhancing and illicit drugs policies may have to be reviewed.

"We have had well researched, well considered policies and had them in place for some time, both illicit drugs and our ASADA/WADA policy," McLachlan said.

"We think we've had the right policy setting. I think right now if the policies aren't working, we need to look at them and have a look at what's going wrong.

"After today I think it's time to look at them."

The latest failed tests come hot on the heels of Fremantle tagger Ryan Crowley being provisionally suspended for testing positive to a substance found in a painkiller earlier this month.

He is slated to face the anti-doping Tribunal on May 1.

On the eve of the Essendon findings, McLachlan said there had been no winners in the elongated saga.

He said the AFL had put contingencies in place for any outcome, but if players were suspended it was unfortunate and would impact opposing clubs like any other suspension or injury.

McLachlan also weighed into the debate over the Etihad Stadium roof, saying it would likely be closed more often in 2015.

"I can see there's a lot of people that want it closed," he said.

"If it's bright it should be closed, if it's raining it should be closed."