Manchester United have said Victor Lindelof is undergoing "precautionary investigations" after suffering from breathing difficulties during the 1-0 win over Norwich but added that the problem is not linked to the COVID-19 outbreak at the club.
Lindelof was substituted during the second half of the victory at Carrow Road on Saturday. A number of players and staff tested positive for coronavirus on Sunday, confirmed by PCR tests on Monday, prompting United to shut down first team operations at Carrington.
The Premier League have announced that Tuesday's scheduled trip to Brentford has also been postponed.
"Victor is currently undergoing a series of precautionary investigations. However, he has recovered well from the episode he experienced in the match against Norwich," a United statement said.
"All indications are that this is not linked to any COVID outbreak within the club."
Following the game at Norwich, interim coach Ralf Rangnick said Lindelof did not know what had caused the issue, which saw him replaced with Eric Bailly after 74 minutes.
"He doesn't remember how it happened," Rangnick said. "He had problems to breathe and his heart rate was higher than normal so we had to replace him.
"We've had him checked and had some examinations done by the doctor. So far, everything seems to be OK but he still seems a little bit shocked."
United are next in action against Brighton at Old Trafford on Saturday.
Under UK government guidance, anyone testing positive for coronavirus must self-isolate for 10 days and sources have told ESPN that United are awaiting further guidance from the Premier League about whether the fixture can go ahead as planned.
On Tuesday, the Premier League said players will undergo daily coronavirus tests as part of emergency measures approved by clubs to deal with the worsening pandemic in England.