Their evidence will be preceded by an opening statement from attorney Chris Venturas, who has represented the 15 players in dispute with ZCU ever since the removal of national captain Heath Streak six months ago.
And at some stage he will give evidence of a private nature to allege racism against him personally by ZCU directors.
The players wanted a leading advocate, Adrian de Bourbon, but were unable to afford him.
The ZCU is expected to be represented by advocate Chris Andersen, who has been briefed by their own attorney and former president Alwyn Pichanick.
The hearing, which is expected to take at least two days, will be held at the Crowne Plaza hotel in downtown Harare, and will be not be open to the press and public.
It will be conducted by the solicitor-general of India, Goolam Vahanvati and a senior South African high court judge Steven Majiedt. They were appointed about two months ago by the ICC after prolongued lobbying by the players for a hearing.
"I'm afraid the public and press must be excluded," Vahanvati told AFP on Tuesday. "We will of course make our report directly to the ICC as soon as practicable. The hearing will have no pre-set format, but we will take both written and oral evidence."
Hostilities deriving from claims by Streak that national team selections were based more on colour than merit, increased week by week after the sackings of 15 white players, who went on strike following what they saw as his unfair dismissal on April 2 this year.
Some of the former player witnesses, who might include Streak, Grant Flower, Alastair Carlisle and Bryan Strang, are also expected to describe instances of alleged personal racial abuse by directors and others on the ZCU.
In its turn the ZCU will allege historical racism by whites in Zimbabwe cricket, including a claim they did next to nothing to assist and encourage blacks into top levels, even 20 years after independence. This, they will say, forced them into an integration policy which has been widely misunderstood.
The replacement Zimbabwe team, nearly all black and averaging 21 years old, is presently touring Pakistan, but will not play Tests.
They have suffered a long succession of heavy defeats by Sri Lanka, India "A", South Africa "A", India, Sri Lanka again and a modest Pakistan representative since Australia declined to play Test matches against them.
They are due to resume Test cricket against Bangladesh in January in the hope they will have reached sufficient standard by then.