ASADA could have a decision on whether two key witnesses will be compelled to testify in its anti-doping case against 34 past and present Essendon players as early as Friday.

Lawyers for ASADA, the AFL, the Essendon players and one chemist were in Victoria's Supreme Court on Wednesday, as the anti-doping authority sought orders to compel Shane Charter and Nima Alavi to give evidence at a future tribunal hearing.

Much of the argument focused on the nature of the playing agreement between the AFL and the players.

The Australian Sports Anti-Doping Authority says the AFL is a commercial enterprise and the players are participants of that business.

It wants the court to grant subpoenas under the Commercial Arbitration Act.

Dan Star, for ASADA, said the players "have contractual dealings with the AFL that have nothing to do with employment".

Barrister Anthony Rodbard-Bean, acting for Mr Alavi, says AFL players are employees.

"They don't carry on business," Mr Rodbard-Bean said.

"However exotic the relationship between the players, the club and the AFL, at the end of the day it's basically an employment agreement."

Mr Rodbard-Bean said the collective bargaining agreement players signed included provisions for leave, including long service leave, and spelled out conditions of pay.

"What is it here that takes us out of employment," Mr Rodbard-Bean said.

Neither Mr Alavi nor Mr Charter were present in court, and Mr Charter was not represented.

Mr Charter provided the court with an affidavit stating he was adopting Mr Alavi's position.

The hearing will continue on Thursday, and Justice Clyde Croft indicated he may make a decision as early as Friday.

The tribunal hearing where Mr Charter and Alavi may be required to give evidence will be a closed hearing, and it will rule on anti-doping infraction notices against the 34 players.

The tribunal hearing is due to start on Monday, though witnesses aren't likely to be called until January.