AS THEY commence their post-season revelry footballers are being subjected to "substantially more" tests for illicit drugs than ever before.

AFL chief Andrew Demetriou revealed yesterday that he sent a memo to every club chief executive and football manager last week asking them to remind their players that, while they might not be playing, they were still being watched.

"It was just reminding them about this period coming up. I won't go into the detail," Demetriou said, confirming that it was the first time he had felt moved to issue such an edict.

"We've spoken to the clubs, make no mistake," he said. "All the clubs, I can assure you, like us have had briefings and understand the importance of this period. Particularly the clubs that finish in the competition.

"In so far as general issues relating to behaviour, I've got absolutely no doubt that the clubs have put things in place to try and minimise the incidence of (poor) off-field behaviour. They've had briefings with their players and they certainly know our views.

"Everyone knows that this time is a very, very important time and a very critical time for them."

Adrian Anderson, the league's general manager of football operations, said that footballers would be tested like never before during this summer.

"I would say there would be more than double the testing during that period than there has been in the past," Anderson said. "There will be substantially more testing than there has ever been before.

"We've increased the number of tests across the board … and we've increased the number of target tests and it's an obvious risk period at that time of year.

"I think the off season in general is a high risk period."

Demetriou confirmed that members of the AFL Commission and the league's executive remained committed to volunteering themselves to undergo drug tests.

This was something they guaranteed when the playing body agreed to accept the league's illicit drugs policy in 2004.

"I'm not discussing how many times I've been tested, I wouldn't know who else has been tested and I don't know any of the results because it's confidential," Demetriou said.