Matches across all three tiers of professional rugby league this weekend are set to fall victim to the rise in Covid-19 infections.
Two fixtures in Betfred League 1 have already been postponed, while Sunday's Championship match between London Broncos and Widnes has been cancelled.
There are also serious doubts over the Super League fixtures featuring last Saturday's Challenge Cup finalists, with Castleford and St Helens both thought to have reported positive tests.
St Helens, who were victorious at Wembley, are due to host Hull KR on Friday, while Castleford are scheduled to play Catalans Dragons in Perpignan on Saturday.
A decision is expected on Wednesday morning and, if both fixtures are postponed, efforts will be made to rearrange Hull KR's trip to Perpignan, which was originally due to be played on July 5, in order to ensure the Catalans do not lose another home game.
The Dragons, top of the table and on a club-record nine-match winning run, are now permitted crowds but have played all-but five of their 15 league and cup fixtures so far this season in England.
Thursday's round 15 fixture between Leigh and Warrington was called off on Monday, after the Wolves reported another positive test, on top of the ones that caused the postponement of their previous game against Hull KR.