Football Association chairman Greg Clarke has said it is hard to see fans returning to matches “any time soon”.
If the Premier League and Football League seasons resume, those matches will be played behind closed doors.
The Premier League is also preparing for the possibility of playing the 2020-21 season without fans.
“The reality is that we just don’t know how things are going to pan out,” Clarke wrote in a letter to the FA governing council.
“But with social distancing in place for some time to come we do face substantial changes to the whole football ecosystem.
“For example it’s hard to foresee crowds of fans – who are the lifeblood of the game – returning to matches any time soon.”
Clarke warned of an FA budget cut of £75m this year, with a “worst-case scenario” of a £300m deficit over the next four years impacting “every area of the game”.