The ECB held a meeting with 18 first-class counties and the county boards on Wednesday, where it informed that it expects a minimum shortfall of 106 m in the current fiscal.
Curran, who went into self-isolation in his hotel room at the Ageas Bowl after he felt ill, had given his sample on Thursday.
ECB's director of special projects Steve Elworthy that the board has already been in touch with the cricket boards of Australia, Pakistan and Ireland to work out a schedule.
The Test series, to be played in a bio-secure environment from July 8 to counter the COVID-19 threat, is subject to the final approval of the UK government.
The England batsman felt that three weeks to 'prepare to go and play in the World T20 in October-November' is enough.
The ECB had previously announced that no cricket would be played until May 28 but that date has now been extended in view of the prevailing situation.
According to the ECB, financial assistance will be made available at every level of the game across counties, boards and clubs.
The cricketing body will meet as needed to review the position and make further decisions as the UK situation unfolds.
England and Wales Cricket Board (ECB) said in a statement that it will make an assessment of all-rounder Ben Stokes' availability after the conclusion of the trial in Bristol.