West Ham, Brighton and Arsenal opened their training grounds to players on Monday as Premier League clubs took their first steps towards a potential re-start.
The English top-flight is reportedly eyeing a resumption of the season on June 8 behind closed doors due to the coronavirus pandemic.
"Project Restart" could see the 20 Premier League clubs resume full training by May 18, allowing players a three-week "pre-season".
Premier League chiefs, due to meet with clubs on Friday, are committed to finishing the season, with Liverpool on the brink of their first title for 30 years.
Brighton said in a statement on Monday that the club were allowing "restricted external access to the training pitches for first-team players only, for non-compulsory individual training".
"Players will need to book and be allotted staggered arrival slots, allocated their own area to train and expected to fully adhere to social distancing rules while doing so, and when arriving and exiting the facility."
A West Ham spokesman said players in apartments or without safe access to green spaces were permitted access to training pitches.
"Access will be limited to one player at a time and all sessions will be in line with government guidelines around social distancing," he said.
Arsenal confirmed on Saturday that players would be allowed to return this week but access would be carefully managed.
It was unclear whether manager Mikel Arteta, who tested positive for the virus last month but has since recovered, was present on Monday.
Britain, on lockdown until May 7 at the earliest, has been one of the countries hardest hit by the pandemic, with more than 20,000 deaths.
Germany's Bundesliga is ready to return to action on May 9 without spectators, if the German government gives it the green light.
Serie A sides will be allowed to return to individual training on 4 May and team training on 18 May after Italian Prime Minister Giuseppe Conte revealed the first stages in lifting the country's coronavirus lockdown.
