Carlisle United have postponed three games over the next 10 days after positive Covid-19 cases at the club.
The English Football League were informed Saturday's trip to Mansfield, the midweek game with Leyton Orient and the 23 January visit of Forest Green could not be fulfilled.
As per government guidelines, members of the squad are now self-isolating.
A club statement said the position had "deteriorated quickly" and an EFL investigation will take place.
"The club's football training activities will now close, and will only reopen when it is safe to resume," the stratement added.
"The safety of our players and staff is paramount, as well as their families and other participants in our upcoming games."
Rescheduled fixture dates will be confirmed in due course and Carlisle's next game will be a trip to Newport County on Tuesday 26 January.