Four players tested positive for coronavirus in the latest batch of tests conducted by the English Premier League and announced on Wednesday.
"The Premier League can today confirm that on Monday 25 May and Tuesday 26 May, 1008 players and club staff were tested for Covid-19. Of these, four have tested positive from three clubs," the league said in a statement.
"Players or Club staff who have tested positive will now self-isolate for a period of seven days."
Since players returned to limited group training on Tuesday, 12 positive tests for the virus have been confirmed at England's top-flight clubs.
No matches have been played in the Premier League since March, but the government has given the go-ahead for elite sport to resume from June 1.