The English Football League says it has told clubs not to return to training until May 25 at the earliest.
The news follows a meeting of the EFL Board on Wednesday, as the League continues to grapple with the logistical and financial issues caused by the coronavirus pandemic.
Premier League players are potentially set to return to training next week, with the intention being to play the remaining matches of the season behind closed doors.
But there remains no clarity on when or whether the Championship, League One and League Two will be back.
The initial proposed date for a return to training was May 16, while EFL chairman Rick Parry has said the current season needs to be concluded before July 31.
Wednesday's EFL statement read: "While there is much debate and discussion taking place publicly and privately regarding what should, or could, happen next, the EFL will continue to undertake consultation with our members before the next steps are determined.
"Current attention is clearly on the immediate next steps, but the long-term impact on the League and its clubs remains as stark as previously outlined, and solutions are still required to fill the financial hole left by the crisis.
"The consequences of the COVID-19 pandemic will not be rectified simply by a return to play behind closed doors.
"In addition, the EFL is mindful of the pressing need for clarity in a number of areas, including the practicalities and timeframes of clubs being able to facilitate a return to training.
"To address this, clubs have today been issued with the latest draft of the EFL's 'Return to Training Protocols', so that they can prepare appropriately.
"However, until all outstanding matters are concluded, including finalising a comprehensive testing programme on matchdays and non-matchdays, the EFL Board has informed its clubs that a return to training should not take place until 25 May at the earliest.
"Dialogue continues with our colleagues across the footballing and political landscape regarding these and other issues, and the EFL is committed to keeping all relevant parties updated on key decisions and developments as they occur."
The EFL has said before it would need 56 days to complete all of the remaining fixtures (326) across all leagues, excluding play-offs.
Leagues One and Two are due to meet on Friday to discuss the matters talked about in the board meeting