Cardiff City manager Neil Harris is resigned to playing football matches at empty stadiums until next year.
Harris fears the Covid-19 pandemic could mean games without fans throughout the 2020-21 campaign, unless a vaccine is found.
Sports governing bodies have been told there may be no return of spectators until March 2021.
"Are we going to get them back this season? Unless we find a vaccine it is going to be very difficult," he said.
"I don't want too scaremonger and have had no information. But i think it could be leading into next year.
"We have to allow the scientists to continue to work and get the breakthrough and go month by month in the footballing world.
"It's certainly not going to be this side of the New Year that's for sure.
Seven EFL clubs piloted small crowds last week and fans were due to return to sports events in limited numbers in England next month.
But UK Prime Minister Boris Johnson said on Tuesday that this will not go ahead and Harris says the situation was a "major concern" for the English Football League and non-League.
"The knock-on effect financially within the game is huge, absolutely massive. The Premier League might not feel the hit because of TV revenues. The Championship will," Harris added.
"Yes we are fortunate football clubs have wealthy owners. But pockets only run so deep when they run other businesses which might be struggling as well.
"Below that in League One and League Two, a lot of those clubs rely on match day revenue and social networks in bar and facility areas.
"They are not open, the revenue has gone and I for one don't see fans coming back before Christmas that's for sure."
Cardiff entertain early Championship leaders Reading on Saturday looking for their first home win after last weekend's 2-0 victory at Nottingham Forest.
Joe Bennett is improving after suffering a calf strain at Forest, though Republic of Ireland international Greg Cunningham and youngster Joe Bagan are on stand-by.
Winger Josh Murphy has returned to training after a hamstring problem.