Steve Bruce confirmed after Friday's 2-0 win at Crystal Palace that three players and a member of staff had tested positive for the virus.
Further tests over the weekend are reported to have produced more positive results and it is unclear when the first-team squad will be able to return to training at the club’s Benton headquarters.
Newcastle travel to Villa Park in Friday's evening kick-off but could request that the fixture be postponed if the outbreak accelerates over the coming days.
The fixture would become the first to be postponed in the Premier League since the first wave of infections forced the entire top flight to shut down in March.
The Premier League has previously issued guidance to clubs suggesting that postponements will only happen if a club has fewer than 14 fit senior players - 11 starters plus three substitutes.
After Friday's win at Selhurst Park, Bruce said the developing situation at the St James' Park club was a "concern" and "difficult to manage".
“We’re trying our utmost to safe as safe as we can," he said.
"My concern isn’t just the welfare of the players, which is vitally important, it’s members of my staff too. We’ll do our best, but it’s difficult at the moment.”
The Premier League reported 10 new cases of Covid-19 from 1,381 samples in the latest round of testing between 23 and 29 November.