Premier League clubs will return to training in small groups from Tuesday after the latest stage of "Project Restart" was approved on Monday.
Clubs unanimously voted to allow players to start socially distanced training in a bid to resume the season next month.
However, Premier League chief executive Richard Masters admitted a target return date of June 12 may prove to be too ambitious.
"June 12 was a staging post; it wasn't a firm commitment and what we don't want to do is continue to move it around," said Masters following a meeting of with the 20 top-flight clubs.
"It really depends on when we can start full contact training and we have a process to go through before we can get to that stage. Of course we've got to be flexible."
Masters confirmed the results from the first round of testing, conducted on Sunday and Monday, would be back by 2pm (1300 GMT) on Tuesday. Testing will continue regularly throughout the training period.
"Strict medical protocols of the highest standard will ensure everyone returns to training in the safest environment possible," a Premier League statement said.
The training protocols were presented to players and managers last week before being rubber-stamped during Monday's video conference call.
The first step requires training to last for no more than 75 minutes for any single player, and with groups of a maximum of five players in each mini-session.
Players will be asked to leave three parking spaces between their vehicle and any other at the training ground, and arrive wearing kit. There will be no access to communal areas such as canteens or physio rooms.
Newcastle manager Steve Bruce warned on Sunday that his players could "fall down like a pack of cards" with injuries if they are not given enough preparation time to get back up to speed before matches restart.
However, he welcomed the first stage of a return to training.
"I must stress that phase one looks as if it's as safe as it can be. I'm sure everyone will be delighted that we're trying to make that effort," said Bruce.
"In phase one we're allowed to train four to five people on one pitch, so basically a player has a quarter of a pitch to work within, so social distancing is not a problem. We'll train with eight to 10 at a time on two separate pitches.
"Everything is in place in the safety aspect. I've got no issues and I can tell the supporters the players and the staff are as safe as we possibly can be."
- 'Making good progress' -
The resumption of Germany's Bundesliga over the weekend has raised expectations that the Premier League can follow suit.
But some Premier League players remain concerned over returning to work while the virus is still uncontained, with Britain one of the countries worst hit by the crisis.
"Phase one is social distancing individual training with a coach. That's no problem, that's like going to the park," Watford captain Troy Deeney told Good Morning Britain.
"I would say 98 per cent (of players) are very much aware that phase one is very good, I would say 65-70 per cent of people are concerned with phase two. I'd say even higher after that."
However, Britain's Culture Secretary Oliver Dowden said he was still hopeful for a return in mid-June.
"I had some very constructive discussions on Thursday with the FA, the EFL (English Football League) and the Premier League," Dowden told Sky News.
"We are working hard with them to try and get it back, aiming for mid-June, but the number one test is public safety.
"If we can sort that out then we will look to resume by mid-June. We're making good progress."