Hull FC and Salford Red Devils have had their upcoming Super League games postponed following positive coronavirus tests at the former club.
Hull announced on Tuesday that six players and two members of staff had tested positive for COVID-19, while another needed to be re-tested after an inconclusive result.
Five of the players to return positive results, and the one in need of another test, featured in the 54-18 defeat to Salford on Sunday.
While the Red Devils confirmed that tests carried out on their players and staff returned solely negative results, 11 players were required to self-isolate after track and trace analysis carried out by the Rugby Football League (RFL).
Salford took the decision to place the entire matchday squad in self-isolation ahead of further tests later this week.
Hull were due to face Castleford Tigers, while Salford were set for a meeting with Catalans Dragons.
Super League executive chairman Robert Elstone said: "Throughout this crisis our priority has been to ensure we minimise any risk, and the postponement of this weekend's scheduled fixtures involving Hull FC and Salford underlines that approach.
"It left us with another challenging situation, but it is a credit to the solidarity of the Super League clubs who agreed to adjust the fixture list at such short notice."
Catalans will now play Wakefield Trinity on Saturday, and Castleford will go up against St Helens on Sunday.