An incensed Brisbane has come out swinging at Mal Michael after its former full back claimed the Lions could have kept him if they had agreed to a lighter training workload.

Michael told Fairfax he would have stayed at the Gabba if the club had been prepared to allow him extra time off for his Papua New Guinea charity work.

The triple premiership defender is now set to be controversially drafted by Essendon after the Bombers acceded to his request to spend three days a month overseas and make two one-week visits each year.

In a three-page statement released by the Lions, entitled "The facts on Mal Michael", the club said he "never requested a reduced training schedule from the Lions".

Lions chief executive Michael Bowers said Michael's retirement backflip, less than two months after his early release, made the club look amateurish.

Bowers said the retirement deal was the culmination of a "12 month journey" based on open communications with Michael about his indecision to play on.

"Mal has put us in a no-win situation where we either appear commercially naive or openly distrustful of our star players," he said.

"You also have to remember that this is an AFL first. We weren't working from any legal precedent."

The AFL is investigating the matter but chief executive Andrew Demetriou this week said no rules appeared to have been breached.

Michael has also said he will be pursuing $50,000 owed to him by Brisbane as part of a back-ended contract, not as part of any ambassadorial payment involving the club and Papua New Guinea.

The Bombers intend to draft Michael with their first pick in the pre-season draft on December 12, and have already agreed terms of a two-year deal with the 29-year-old.

Brisbane coach Leigh Matthews said he'd asked Michael during and after the season whether he wanted to leave the club but was told he was considering retiring from the game to set up his PNG foundation.

"I asked Mal if he had any interest in playing anywhere else and whether this 'reduced training schedule' I kept hearing about was something we should discuss," Matthews said.

"Mal said neither of those things were an issue because he intended to spend one week in every three in Papua New Guinea.

"This clearly makes it impossible to play professional footy on any basis.

"It sticks in my memory that Mal said he had a 'once in a lifetime' business opportunity over there."