The pair tested positive to the banned substance clenbuterol on February 10, just two days after the side returned from a pre-season camp in New Zealand.

They were told of their positive test result last Friday.

What is clenbuterol?
A season of opportunity gone? 
Keeffe, Thomas test positive

Speaking on Triple M radio on Tuesday morning, McGuire said he had no time for drug cheats, but would fight for Keeffe and Thomas if there were "mitigating circumstances".

He hoped to meet with the two over the next few days and noted they were protesting their innocence.

"I'm pretty straight forward on these things; if people have taken performance-enhancing drugs you get your whack – it's as simple as that.

"If you haven't, if there's mitigating circumstances, then let's work through that situation.

"I want to underline this 15 times; when the players were told the news they were absolutely flabbergasted and it wasn't acting or anything else like that – they had no idea whatsoever in the first instance.

"I'll hopefully speak to them in the next 48 hours, but their position is they have no idea how this could have happened."

Collingwood expects to see the results of the players' 'B' samples on April 14.

If that is positive Keeffe and Thomas will front the AFL Anti-Doping Tribunal.