Newcastle United have been trying to contain the spread of Covid-19 for at least two weeks - and senior staff believe they should have been tested more frequently this season.
A backroom member tested positive more than a fortnight ago and the club do not yet know if that was linked to the outbreak that caused the postponement of Friday night's trip to Aston Villa.
A player who was away during the recent international break also tested positive, but only after he had returned to the club and was around the first-team set-up.
Newcastle United have been trying to get a grip on a Covid-19 outbreak for two weeks
The training ground remains closed and Friday's trip to face Aston Villa has been postponed
However, the virus had already affected at least one other individual in the period between the 2-0 defeat at Southampton on November 6 and the 2-0 loss at home to Chelsea on November 21.