The Premier League has confirmed the game between Brentford and Manchester United on Tuesday has been postponed due to a Covid-19 outbreak at the Old Trafford club.
The Red Devils had to close their first team operations at the club's training ground following a raft of positive coronavirus test results.
A statement from the league reads: "The Premier League Board has decided to postpone Brentford’s home fixture against Manchester United, due to be played on Tuesday, 14 December at 19.30 GMT.
"The decision was taken following guidance from medical advisers due to the exceptional circumstances of an ongoing COVID-19 outbreak within Manchester United’s squad.
"First-team operations at the club’s Carrington Training Complex were closed down today to help control the outbreak and minimise risk of further infection among players and staff.
"The League wishes a quick recovery to those players and staff with COVID-19. The postponed fixture will be rearranged in due course.
"With the health of players and staff the priority, and in light of the recent rise in COVID-19 cases across the country, the Premier League has reintroduced Emergency Measures.
"These include protocols such as more frequent testing, wearing face coverings while indoors, observing social distancing and limiting treatment time."
A United statement added: "Manchester United can confirm that our Premier League fixture at Brentford FC, on Tuesday 14 December at 19:30, has been postponed and will be rescheduled in due course.
"Following PCR confirmation of positive LFT Covid-19 tests among the first-team staff and players, the outbreak requires ongoing surveillance. A decision was taken to close first-team operations at the Carrington Training Complex for 24 hours to help minimise risk of further infection, and individuals who tested positive are isolating in line with Premier League protocols.
"Given cancellation of training and disruption to the squad, and with the health of players and staff the priority, the Club requested the match to be rearranged. The Premier League Board took the decision to postpone based on guidance from medical advisors.
"Manchester United regrets the inconvenience caused to Brentford FC and to the fans of both clubs by Covid-19."
A number of clubs are being affected as coronavirus cases rise throughout the United Kingdom. Tottenham, Leicester, Brighton and Aston Villa have all dealt with new infections recently.
The Premier League confirmed on Monday that the latest round of testing had returned 42 new coronavirus infections, the most recorded ever over a seven-day period and the highest amount taken in a single week since figures were first announced in May 2020.
Brentford added: "We wish everyone affected a speedy recovery and look forward to hosting Manchester United at the Brentford Community Stadium in the new year."