Ten Premier League players or staff members were positive for COVID-19 in the latest round of testing.
The number of positive tests is on the rise, after there were three or four positives in each of the last three weeks.
This is the highest number of positive results announced by the Premier League after a round of testing.
A statement read: "The Premier League can today confirm that between Monday 21 September and Sunday 27 September, 1,595 players and club staff were tested for COVID-19.
"Of these, there were 10 new positive tests.
"Players or club staff who have tested positive will self-isolate for a period of 10 days."
Previous test results
Round 1: 31 August-6 September - 1,605 tested, with three positives
Round 2: 7-13 September - 2,131 tested, with four positives
Round 3: 14-20 September - 1,574 tested, with three positives