Two shattered Collingwood players who tested positive to a banned drug have expressed their innocence as they now prepare to fight a potential ban.

Lachie Keeffe and Josh Thomas, both Queenslanders, good friends and now provisionally suspended, have returned a positive 'A' test to  clenbuterol. The B sample has yet to be tested.

The players and Magpies chief executive Gary Pert and football department chief Neil Balme were told of the positive test by the Australian Sports Anti-Doping Authority on Friday.

"Then when they rolled out who the two players were, I must admit I was pretty devastated because we are actually talking about two of the highest quality young men as part of our program. I think everyone would have felt the same, quite surprised and devastated. Things unfolded from there."

Pert said he had spoken to the players and ensured they were ready to go through the legal "process", rather than seeking answers.

"At this point the players have not conveyed anything to club to explain the positive result," he said.

"The only facts I have is that they tested positive to the substance I said. When we spoke to the players and we said, can you see any reason for this positive test, and they both answered no.

"When we spoke to the players, I would say they looked close to being in shock on Friday. You have to keep in mind these are two young men who were at home and had ASADA knock on their door. Both Neil and myself spoke to them shortly after."

Pert would not speculate where the drug may have come from but said ASADA had confirmed there were no other players involved.

The Magpies will meet with players this week to look at whether they remain with the club and train through the process.

"We are hoping there is a good outcome but we are accepting at the moment they are not going to be available and it could be for some time," Balme said.

The experienced footbal chief said the two men were stunned to be told of the positive test.

"It was disbelief of both of them. They both said: 'We haven't done this'," he said.

"We know what it is. That is one of the reasons why we think why would they? They would have to be actively pursuing it and wanting it. If you look at both of these players, it doesn't make any sense for either of them to use this because they are both quite lean ... they don't need it, they are very fit."

Keeffe, a defender, was part of the club's leadership group, while Thomas is a talented midfielder.

Pert said the Magpies had completed a forensic audit of their dietary and nutrition program to ensure it was not to blame.

"It (the review) is completely satisfied the positive result is in no way connected to that program. The Collingwood dietary and nutrition program is tightly controlled. Everything is recorded and is overseen by an independent integrity officer," he said.

Coach Nathan Buckley broke the news to the full playing group on Monday morning, as they now prepare for the season opener against the Brisbane Lions on Saturday night.