The Premier League has confirmed six positive coronavirus tests, out of 748 staff and players.
Those six tests have come from three clubs, reports the Mirror.
All those that tested positive will now have to self-isolate for a period of seven days, the Premier League confirmed.
But the individuals that tested positive, or the clubs they represent, were not named.
In a statement, the Premier League said: "The Premier League can today confirm that, on Sunday 17 May and Monday 18 May, 748 players and club staff were tested for COVID-19.
"Of these, six have tested positive from three clubs.
"Players or club staff who have tested positive will now self-isolate for a period of seven days.
"The Premier League is providing this aggregated information for the purposes of competition integrity and oversight.
"No specific details as to clubs or individuals will be provided by the Premier League due to legal and operational requirements."
Premier League clubs voted on Monday to initiate 'Phase One' of Project Restart, which includes a return to training in small groups.
Players from across the top flight, including at champions-elect Liverpool, reported to their training grounds on Tuesday.
Top flight chiefs and the government are keen for action to get back underway with June 12 the current aim for the season to restart.
But the Premier League are flexible with the date, depending on how the situation evolves over the coming weeks.
Some players, such as Watford skipper Troy Deeney, have spoken out over a potential restart.
Initially, the plan was for games to take place at neutral venues, but it now seems likelier that matches will be played home and away.
Fans will not be in attendance, with Manchester United asking their supporters to stay away from matches when they do resume in a statement on Tuesday.
"It is now widely accepted that any matches that may take place will only do so behind closed doors," they said.
"We share your disappointment that you will not be able to watch United in person from within the stadium, but we would encourage you to give your continued loyal support from the comfort and safety of your home.
“To help with that, the Premier League and their media partners will work to deliver the very best broadcast coverage of our games.
"We also ask for your co-operation not to travel to any stadiums at which we are playing on match-days.
