Six Hull FC players have tested positive for coronavirus, the Betfred Super League club have announced.
It has forced their scheduled training session on Wednesday to be cancelled, in addition to that of Salford.
The two teams played each other on Sunday in Super League, with the Red Devils winning 54-18 at Emerald Headingley Stadium.
Five Hull FC players who were involved in the match have since recorded a positive Covid-19 test while a sixth, who was not in their matchday 17, has also tested positive.
Another is due to have a retest after an inconclusive result and all those who tested positive are now required to quarantine for 10 days until August 21 in line with national guidance.
Two members of Hull's coaching staff have also tested positive with Public Health England informing the club and Salford of the news on Tuesday evening.
A statement from the RFL read: "Salford's routine weekly test results have not yet been received.
"But the RFL is now analysing Sunday's match to determine how many players from each team will also be required to self-isolate under the test and trace procedures that have been agreed with Public Health England.
"Announcements on the impact on forthcoming Betfred Super League and Coral Challenge Cup fixtures over the next two weekends will be made as soon as possible."
