Watson and Fletcher, understood to be part of the 34 past and current Bombers to be issued with show-cause notices, of whom 17 are still at the club, opted to have their provisional suspensions lifted in order to play in the one-off Test against Ireland in Perth.

AFL Players Association chief Paul Marsh confirmed that this decision has meant the back-dating of any suspension will not be as great for the veteran pair.

"I think you have to go back to when that actually happened and that was right around the time that provisional suspensions were put in place. Those two particular players had their provisional suspensions start a week later and that will impact until the end of this," Marsh said.

"If the players are found guilty, that one extra week will be a factor for those two. But one week versus the four of five month credit they have built up, is two significantly different things."

However, this could conceivably mean that Watson and Fletcher would have to sit out an extra week of the home-and-away season should any suspension be backdated until the end of last season.

In a statement issued to Fairfax Media last week while the Bombers weighed up their playing options for the NAB Challenge, the Australian Sports Anti-Doping Authority  made it clear what it felt about the potential lifting of provisional suspensions.

ASADA said under the AFL's anti-doping policy that "if a provisional suspension is imposed and respected by the player, then the player shall receive a credit for such period of provisional suspension against any period of ineligibility which may ultimately be imposed.

"Our view is any athlete competing during their provisional suspension and prior to a final decision by a sport tribunal, has not respected their obligation under the World Anti-Doping Code and should not be entitled to a credit for the provisional suspension. The World Anti-Doping Code is very clear in this respect and our duty is to ensure sports comply with their responsibilities to the code."

All 25 Essendon players who were on the 2012 list when the contentious supplements program was run will not play in the NAB Challenge, ensuring the privacy of those fighting to clear their names in the ongoing AFL anti-doping tribunal hearing is protected to the best it can be.

The Bombers on Saturday began contacting VFL clubs and player agents, needing to procure 15 or more top-up players for the NAB Challenge, beginning against St Kilda at Morwell on March 7. About eight are expected to come from Essendon's VFL team, although one man on that playing list — understood to be former AFL player Kyle Hardingham — cannot play because he is part of the charged group of 34.

This process will also intertwine with the club's home-and-away campaign, for anti-doping tribunal chairman David Jones is not expected to unveil his findings at least until days before the Bombers take to the field in round one against Sydney on April 4.

"We are absolutely talking about that, we have to. It's only six or so weeks away. We have started talking about that. As you can imagine, it's complex," Marsh said on 3AW.

"We are going to talk through issues like how are we going to pay the top-up players, what insurance will be in place, what happens if they have to quit jobs to come and play in the competition, how the salary cap will be impacted.

"They are all the conversations that are taking place. There is a lot of work going into it."

Marsh still hopes the players will be cleared of being administered the banned drug, thymosin beta-4.

"Hopefully it will all be wasted work and the players will be exonerated," he said.

"But you can't wait until the verdict is handed down here and start thinking about. I am confident if the worst happens we will have answers as to what we do next."

It is believed ASADA's written submission against the players and given to Jones runs to more than 300 pages.

The hearing, at which the architect of the supplements program Stephen Dank has also been charged, resumes on Monday, with counsel for ASADA, the AFL and the players to deliver their final oral submissions. Dank maintains he did not give the players banned drugs.