Exeter Chiefs chairman Tony Rowe has warned Gallagher Premiership clubs could go bust if fans cannot return to matches by Christmas.
The Premiership will resume on Friday after a five-month shutdown due to the coronavirus pandemic, but games will be played behind closed doors.
Exeter were the only profitable top-flight outfit last year, but Rowe has admitted fearing for clubs' futures if fixtures are not played in front of fans in the long-run.
"I don't think the rugby fraternity realise how much clubs are losing and it's currently costing us just over £1million a month to keep operating," said Rowe.
"We still have to maintain all the infrastructure, as well as the playing side, so it's been incredibly difficult.
"Central funding is made up of TV, league sponsors and RFU money, which covers some of it, however, the bigger money comes from bums on seats and if we can't get spectators into the stadium, we're all going to be in trouble.
"Most of the clubs will have worked out how long they can survive, but if we can't get some decent revenue coming in by the New Year, we've got serious problems.
"Here at Exeter, because we have been commercially sound for the last 20-odd years, we're fortunate we've been able to lean back on some of our assets to help raise the funds we need to keep going, but I do fear for some of the other clubs."
High-flying Exeter were able to secure all their top players onto new contracts following the impending salary cap reductions without issue.
The Chiefs will again be pushing for the Premiership title when the season finally gets back into swing, with Rob Baxter's men poised to remain as competitive as ever on the field.
But despite having one of the league's most robust business models in normal circumstances, Rowe admitted Exeter have been hit just as hard by the pandemic as anyone else.
"Sandy Park, as a business, has already had to cancel over £1million in corporate business from banquets, conferences and dinners and right now I can't see when they will come back, so it's eating into our reserves pretty quickly," said Rowe.
"Everybody has held up Exeter as the ideal business and a profitable club because we have Sandy Park Conference and Banqueting that pays the day-to-day bills and then we have all these bums on seats for match-days.
"However, for the last five months that's been a millstone around our necks. At the moment, we can't earn any revenue, yet our outgoings remain the same.
"What was to a degree our golden goose in having Sandy Park pay the bills and the overheads, whilst the match-days were the big earners, both of those income streams have currently gone."