Two Warriors players were already self-isolating after receiving positive test results on Tuesday and that went up to three following a series of re-tests.
However, only one of the three played in last Saturday’s Challenge Cup semi-final defeat by Leeds, whose fixture against Castleford on Thursday is also set to go ahead.
The identity of the players has not been revealed, and the Wigan club cancelled training on Tuesday as a precaution, while awaiting the results of the weekly tests carried out on the rest of their squad and support staff.
Lam said: “Of the results that came back, there were four that were inconclusive so they were re-tested last night and, since that time, one player in that group of four has also been tested as positive.
“He didn’t take part in the game on the weekend, so there’s no issues there.
“The issues will come in selection and naming our team. There’s going to be a bit of juggling and the team won’t be settled probably until the day of the game.
“We’re powering on, as all clubs have done in this situation.”
A spokesman for the Rugby Football League said it was waiting for all the results to come through from the other clubs before publishing its weekly round-up.
Lam admits it is an anxious time for coaches but insists all the clubs are endeavouring to complete the season.
He added: “It’s a nightmare. I’m sure it’s the same for all the coaches. You sort of hold your breath waiting for the results.
“They come around 30 hours after you get tested and, when you get the text through from the welfare office that it’s all clear, it’s a sigh of relief.
“You dread the moment but you’re aware that it’s highly likely to happen.
“When you consider what is happening in the UK at the moment and the rise in cases… it’s going to happen.
“I just hope as a sport we can contain it for the safety of everyone involved.”
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