Leinster are further examining results of their latest covid tests.
Leinster and Munster's St. Stephen's Day meeting has been postponed.
They were due to play the first inter-pro derby of the festive season on Saturday.
Leinster have released a statement to say they're investigating the outcomes of some of the results from their latest round of Covid-19 PRC testing.
PRO14 Rugby will examine potential dates in early 2021 to reschedule the game.
Connacht's game with Ulster on Sunday is still due to proceed.