Leinster's Heineken Champions Cup last-16 match against Toulon has been called off after an unnamed Toulon squad member tested positive for Covid-19.
The French side were already in Dublin in preparation for the Friday evening fixture.
With the quarter-finals scheduled for next weekend, it appears unlikely that the fixture will be rearranged.
The winner of Friday's match was set to meet Exeter Chiefs or Lyon on Friday 9 April.
During the group stages of the tournament, any side unable to fulfil a fixture due to a Covid-19 case were deemed to have lost the game. Should the same principle apply to the knock-out stages, Leinster will advance to the last eight.
This season's competition has looked radically different to its usual format, and has had to contend with the challenges posed by the ongoing pandemic.
January's remaining pool fixtures were scrapped following French government concerns regarding cross-border travel.
The semi-finals are scheduled for the weekend of 30 April with the final set to take place on Saturday 22 May, although it will no longer be held in Marseille.
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