Pool B of the Heineken Champions Cup has been thrown into chaos as a result of an outbreak of the Covid-19 coronavirus at Exeter Chiefs.
The reigning champions' match against Toulouse this weekend has been cancelled, as has the clash involving Glasgow Warriors and Lyon because a number of the Scottish club's players are self-isolating having faced Exeter last weekend.
The result of the games will now be decided by Match Result Resolution Committee which has been convened by tournament organiser EPCR.
Those decisions will have big ramifications for three Irish provinces competing for four quarter-final spots in the hugely competitive Pool B.
Exeter, Toulouse and Lyon are all on five points after securing bonus points in their opening weekend wins.
Munster, Ulster and Connacht will be watching the outcome closely and could profit if the results are declared draws.
"EPCR has been informed that a number of Exeter players and staff have tested positive for COVID-19, and that in accordance with public health guidelines, the club will not be able to send a matchday squad to fulfil its fixture against Toulouse. The Pool B match is therefore cancelled," an ECPR statement read.
"As Exeter played against Glasgow in round one of the tournament, Glasgow Warriors have advised EPCR that many of its senior players are now self-isolating in accordance with guidelines from Public Health Scotland and consequently the club is not in a position to field a matchday squad of the appropriate standard for its round two fixture against Lyon.
"The Pool B match between Glasgow Warriors and Lyon is therefore also cancelled.
"As per its COVID-19 protocol, EPCR will convene Match Result Resolution Committees to determine the results of the cancelled matches and the decisions of the committees will be communicated as soon as practicable."
By his own admission, Josh van der Flier endured an unsatisfactory few months with Ireland, so potentially finding himself on the bench for Leinster's Heineken Champions Cup opener or, even worse, left out of the match-day squad entirely would have been entirely unwanted.
Connacht almost pulled off one of the most famous European wins in the club's history in Paris last weekend, and the manner of their performance against a star-studded Racing 92 side offered plenty of hope that they belong at Europe's top table.
Munster out-half Ben Healy has been ruled out of Saturday's Heineken Champions Cup clash in Clermont due to the shoulder injury he picked up in last weekend's win over Harlequins.