Warrington Wolves and St Helens have each reported that a player has tested positive for coronavirus.
The Wire will now be without seven players for Friday's match against Hull FC, with six already self-isolating after test and trace analysis.
The St Helens player tested positive after showing symptoms, with two of his team-mates having to self-isolate after coming into contact with him.
Wakefield's game with Leeds on Thursday was postponed after two positive tests.
Those two coronavirus player cases at Wakefield led to the six Warrington players having to self-isolate, though they have each returned two negative tests this week.
St Helens' Super League fixture at Huddersfield on Friday will still go ahead.
Meanwhile, Wakefield and Catalans Dragons are set to have further tests on Friday, with results due over the weekend.