A member of England's support staff has tested positive for Covid-19 before Saturday's Autumn Nations Series opener against Tonga at Twickenham.
The Rugby Football Union (RFU) said "everyone" has had lateral flow tests, with no further positives discovered.
The staff member who had a positive lateral flow test is isolating; England are awaiting the results of PCR tests.
England will train on Thursday morning and the team announcement for Saturday has been pushed back to 12:15 GMT.
"The team and staff are following all Covid protocols," an RFU statement added.