Leinster and Munster will return to training today after the IRFU confirmed that the Covid-19 tests carried out on 140 players and staff on Wednesday have come back negative.
The two provinces plan to train in groups of seven this week as rugby takes its first steps towards a return to action in Ireland.
Players and staff at Connacht and Ulster will be tested this week ahead of their planned return to training next week.
The PCR testing was carried out by Cork-based company Advanced Medical Services on behalf of the IRFU.
The players are working towards a resumption of action on August 22 when Leinster play Munster at the Aviva Stadium.
It is not yet known if all players will be present at training, given a number are thought to have concerns about returning to work.
The IRFU last week said nobody would be forced to return.
Training will be quite different to what the players are used to under plans announced last week.
Each player must travel alone to training in their kit because no showers or dressing-room facilities will be available to use, nor will kitchen areas or analysis rooms.
Before being permitted entry to the training centres, each player must complete a daily questionnaire, before having their temperature taken. If the temperature is above 37.5°C or if any of the answers within the questionnaire raise a red flag, a decision on the next course of action for that player will be made.
The same groups of seven players and one coach will work together for the first week and will not be permitted to interact with any other groups.
It is then hoped that come week two, groups of 14 and two coaches will be allowed to mix and train together.
For the first few weeks at least, training schedules will be very basic. Gym equipment will be regularly cleaned, while no breaks will be permitted, in order to limit the amount of time players and coaches spend around each other.