Norwich City s English defender Max Aarons (L) tackles Manchester United s English striker Marcus Rashford (R) during the English Premier League football match between Norwich City and Manchester United at Carrow Road Stadium in Norwich, eastern England, on December 11, 2021. AFP
United halted first-team operations at their Carrington training complex for 24 hours on Monday after several players and staff tested positive for the virus.
Ralf Rangnick's squad will not travel to London for the match until the outcome of the discussions with the Premier League was known.
Aston Villa and Brighton also revealed positive tests on Monday as the virus threatened to wreak havoc on the fixture list.
"Manchester United can confirm that following PCR test confirmation of yesterday's positive LFT Covid-19 cases among the first-team staff and players, the decision has been taken to close down first-team operations at the Carrington Training Complex for 24 hours, to minimise risk of any further infection," a United statement said.
"Individuals who tested positive are isolating per Premier League protocols.
"Given cancellation of training and disruption to the squad, and with the health of players and staff the priority, the club is in discussion with the Premier League whether it is safe for Tuesday's fixture against Brentford to continue, both from a Covid infection and player preparation perspective.
"Team and staff travel to London will be deferred pending the result of that discussion."
It was reported positive lateral flow tests were returned by a small group of United players and staff on Sunday, with those individuals sent home before the training session began.
With the Omicron variant sweeping across Britain -- forcing the government to reintroduce stricter Covid protocols -- United's outbreak comes against a backdrop of growing virus issues at Premier League clubs.
Tottenham's Premier League fixture against Brighton on Sunday was postponed after an outbreak at the north London club left boss Antonio Conte admitting he and his players were "scared".
Conte said last Wednesday that eight players and five members of staff had tested positive, forcing the Europa Conference League match against Rennes to be postponed.
Just moments before United's statement on Monday, Villa manager Steven Gerrard said his team had a virus outbreak, although their game against Norwich on Tuesday is not believed to be in doubt.
Gerrard confirmed "a couple of staff members and a couple of players" had tested positive for Covid-19, which led to Villa cancelling training on Sunday.
However, the squad trained as normal on Monday ahead of their trip to Carrow Road, where United won 1-0 on Saturday prior to their positive tests.
"I made the decision yesterday. On the back of receiving a couple of positive cases, I thought it was just common sense to just cancel the session," Gerrard said.
"We re-tested this morning and we have got a couple of staff and a couple of players missing for the foreseeable future but the vast majority have come through the test this morning and we look forward to competing against Norwich."
Brighton manager Graham Potter said there were "three or four" positive tests among his squad, but their match against Wolves on Wednesday is not currently under threat.
"We've got a combination of injuries and a bit of Covid ourselves," Potter said.
"We've got three or four, I would say, at the moment. And obviously that's something we have to deal with, like everybody else.
"Now we're just checking and making sure it's at that number."
The Premier League wrote to all top-flight clubs last Thursday instructing them to reinstate Covid-19 emergency measures, including a return to social distancing and mask wearing.
Arsenal manager Mikel Arteta last week responded to the increase in virus outbreaks by calling for the Premier League to issue clearer guidelines on how many positive tests should trigger a postponement.
Arteta's side lost at Brentford on the opening weekend of the season when their game went ahead despite four positive tests.
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