The Premier League has confirmed there have been nine positive coronavirus cases recorded in the latest round of testing.
It comes after 10 positive cases were confirmed from last week's testing in the English top-flight, the highest number in any round of Premier League testing so far.
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A statement read: "The Premier League can today confirm that between Monday 28 September through to Sunday 4 October, 1,587 players and club staff were tested for Covid-19. Of these, there were nine new positive tests.
"Players or club staff who have tested positive will self-isolate for a period of 10 days.
"The Premier League is providing this aggregated information for the purposes of competition integrity and transparency.
"No specific details as to clubs or individuals will be provided by the League and results will be made public after each round of testing."
Liverpool's Sadio Mane and Thiago Alcantara have recently returned positive Covid-19 swabs.
The figures last week included West Ham boss David Moyes, and Hammers players Issa Diop and Josh Cullen.
The club announced that the trio had tested positive prior to their Carabao Cup third round game against Hull City on September 22.
Moyes has been managing the team from home, with assistant Alan Irvine having overseen their recent victories over Wolves and Leicester.
The number of Covid-19 cases is on the rise, with three or four positive swabs having been returned weekly in the Premier League over the course of the first three rounds at the start of the 2020/21 season.
On Monday, the Department of Health reported 12,594 new coronavirus cases and 19 deaths in the UK.
Previous Premier League 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
Round 4: 21-27 September - 1,595 tested, with ten positives.