Two Super League matches scheduled for Friday have been cancelled as the coronavirus pandemic threatens to see the conclusion of the season descend into chaos.
Huddersfield's clash with Castleford was called off after the Tigers reported 12 positive coronavirus cases following tests carried out on Tuesday.
Meanwhile, the match between Salford and Warrington is also off after the Red Devils informed the authorities they only had 13 players available for selection.
Although Salford did not cite any further positive tests, their predicament is related to having to play a series of four games in 11 games due to fixture congestion brought about by the crisis.
Competition rules deem that Warrington will be awarded a 24-0 win due to a forfeited fixture, although the matter has been referred to the RFL's Compliance Department for further consideration.
There are fears of further cases given Castleford's testing was carried out one day after they were beaten by Leeds at Headingley.
In a statement, the Rugby Football League said: "The RFL and Super League will today liaise with Public Health England, Castleford Tigers and the Tigers' last opponents, Leeds Rhinos, before the Multiple Case Group meets to consider the data and decide next steps.
"Super League and the RFL are actively exploring all options and will make a further announcement as soon as practicable."
Earlier this week, Catalans Dragons were forced to cancel their scheduled match against Warrington in Perpignan after more of their players tested positive for the virus, raising concerns over their ability to complete the season.
The latest developments also raise questions over the practicability of staging the play-off semi-finals, scheduled for November 20, and the Grand Final at Hull's KCOM Stadium a week later.