Brentford’s Championship fixture against Rotherham United on Saturday has been postponed after positive Covid-19 tests at the Millers.
Players and staff affected will be required to self-isolate in line with government and EFL guidance.
Rotherham are monitoring the extent of the outbreak and their trip to Luton on Tuesday is still set to take place.
The match at Brentford’s Community Stadium has been rearranged for Tuesday, 27 April at 19:00 BST.
Rotherham have closed their Roundwood training ground and the circumstances surrounding the postponement will be subject to an EFL investigation.
It is the second time this season that Rotherham have recorded a Covid-19 outbreak at the club. They had to postpone fixtures against Derby County and Middlesbrough in December following a number of positive tests.
The latest outbreak comes after the most recent set of EFL testing figures, released on Tuesday, recorded the lowest number of positive cases since twice-weekly testing began at all 72 clubs in early January.
Only two positive cases were returned from 5,856 players and club staff who were tested between 22 and 28 February.
Since those figures were confirmed, Rotherham beat Sheffield Wednesday at Hillsborough on Wednesday.
The Millers are third from bottom, three points adrift of safety, while Brentford are second but only above third-placed Watford on goal difference after losing at leaders Norwich City on Wednesday.