Four individuals from three clubs have tested positive for coronavirus in the latest round of Premier League testing.
The league said 1,008 club staff had been tested in all over the course of Monday and Tuesday.
The individuals concerned must now self-isolate for a period of seven days.
The next set of testing will be the first to be conducted when at least some of the Premier League clubs have resumed contact training, which was unanimously approved on Wednesday.
For all the latest sports news, analysis and updates direct to your inbox, sign up to our newsletter.
The Premier League said the number of tests per club would increase from 50 to 60 for the next round, which will be the fourth overall.