A number of people at the club tested positive for the virus on Sunday morning.
Manchester United are the latest Premier League club to suffer an outbreak of Covid-19, GOAL understands.
A number of players and staff returned postive lateral flow tests on Sunday morning and were sent home from training.
There are now fears the outbreak could spread even further, putting Tuesday’s Premier League trip to Brentford in serious doubt.
What do we know?
GOAL understands the whole group who travelled to Norwich on Saturday tested negative in the latest round of routine tests.
However a fresh round of lateral flow testing on Sunday morning returned a small number of postive tests among players and staff.
Those who had tested positive were subsequently sent home, with the Premier League informed of the situation.
Those who remained outdoors with the training schedule adjusted to individual and non-contact sessions.
Source: Goal