The English Football League season can be completed in 56 days when it is safe to resume amid the coronavirus pandemic, clubs have been told.
But it is assumed that matches will be played behind closed doors.
A letter sent to all 71 EFL clubs by chairman Rick Parry said no training should resume until at least 16 May.
The EFL said it was hopeful the campaign could finish in the summer, but there is still no indication of when it might begin again.
All 24 sides in the Championship still had nine matches to play when the league was suspended on 13 March.
Some clubs in League One and League Two have 10 games left.
If the campaign had carried on as normal, the remaining fixtures would have been completed in 73 days up until the Championship play-off final on 25 May.
The EFL estimates it can now finish all matches within two months, including the play-offs, although plenty of sides have already played as many games in such a timeframe earlier in the season.
"How and when we return (including training) is clearly subject to change and any decisions will be taken in conjunction with the government and relevant health authorities," the letter said.
"It is our working assumption at this stage that matches will be played behind closed doors when we eventually return and as part of our contingency planning we are absolutely mindful of the need to try and mitigate the cost of this to clubs as best we can."
The EFL season is currently suspended indefinitely with the last handful of games taking place in League One and League Two on 10 March.
Several sides have already put players and staff on furlough or temporary leave. However, a £125m advance from the Premier League to the EFL and National League will not be distributed "while additional clarity is sought on other financial matters, particularly in respect to player wages".
The letter also suggested the start of next season could be delayed.
"Looking more long-term, the EFL must remain mindful of the implications that the extension of this season may have on the commencement of the 2020-21 campaign, although we will ensure there is a suitable break between the two, so as to allow clubs and staff sufficient time to regroup and prepare accordingly," it added.
"I think there will be a sigh of relief as and when we reach that point, and what is clear right now is that Covid-19 continues to present hugely challenging and uncertain times for everyone, and our thoughts are with all those directly affected by the pandemic."