ASADA has opened its case against 34 past and present Essendon players and one support person before the AFL Anti-Doping Tribunal.

The AFL released a statement on Monday afternoon saying ASADA's opening submissions were expected to continue on Thursday and Friday before the Anti-Doping Tribunal adjourns until January 12.

The Anti-Doping Tribunal, which is being held behind closed doors in the Victorian County Court, will not sit on Tuesday or Wednesday.

ASADA is alleging the players and support person breached the AFL Anti-Doping Code through the use of the banned peptide Thymosin Beta-4.  

The anti-doping authority will need to prove its case without first-hand testimony from potential key witnesses Shane Charter and Nima Alavi.

The Supreme Court ruled on Friday that subpoenas could not be issued to biochemist Charter and compound pharmacist Alavi to compel them to give evidence.

Former ASADA CEO Richard Ings said that made it a "one-all scoreline" between ASADA and the players, with the penalty shootout to come.

Ings noted that while ASADA had a big win in the Federal Court three months ago when it ruled that the joint ASADA and AFL investigation into Essendon's contentious supplements program was legal, Friday's Supreme Court verdict was undoubtedly a setback.

ASADA is still set to present statements from Charter and Alavi to the Tribunal.

But the Herald Sun revealed on Monday that Charter had met with Essendon and one of the players' lawyers to discuss potential weaknesses in ASADA's case.

If found guilty, the players face bans of up to two years.