Ending the French Ligue 1 season early was a "massive error" and one that showed "an obvious lack of leadership", says Lyon president Jean-Michel Aulas.
The campaign was stopped on 13 March because of the global coronavirus pandemic and did not resume.
Paris St-Germain were crowned champions in April, with Toulouse and Amiens relegated to Ligue 2.
Top flights in Germany, Spain, Italy and England resumed in May and June.
Aulas said nobody "outside those who took the decision" understands why the campaign was declared finished.
He told BBC World Service Sport's John Bennett: "All that was needed was to stop temporarily, assess the situation and take a decision on whether to stop later on.
"It is a massive error, firstly because the country needs football and at the moment, to watch football, we are now obliged to turn to football in other countries.
"Above all, we're going to go through a dramatic period for French football that will be deprived of its revenue.
" Best players could go because of financial implications Aulas says the biggest clubs in the country - PSG, Marseille, Lyon and Bordeaux - will be hit the hardest in terms of revenue from ticketing, sponsorship and television, estimating a total loss of between 300m euros and 400m euros.
"It will be harder than before because Lyon is a club that historically is well run with its own funds," said Aulas, whose club were seventh when the league ended.
"[We have had] reserves and had this profitability which allowed us to be able to either sell well when we wanted to - being in charge of the game - or being able to keep the players because there was no need to sell.
" Lyon are still in the last 16 of the Champions League, holding a 1-0 lead over Juventus after the first leg, but failure to progress could see them lose about 70m euros (£63m) for next season.
They are also in the French League Cup final, where they face champions PSG on 24 July, and winning the competition could provide a route into Europe for next season.
But a lack of competitive action means Lyon are looking to arrange friendly matches against other teams who have also not been playing.
Aulas said: "It is very frustrating because also if we don't get into the Champions League - and we are always in Europe, 23 consecutive years with six or seven quarter-finals - the attractiveness of the club will be undermined.
"In August, we are going to meet teams in the these competitions who have been able to prepare better than us.
" Aulas hoping to assemble 'best' women's team Lyon were awarded the French women's title, winning the competition for the 14th consecutive season, and are reigning European champions.
England internationals Lucy Bronze, Nikita Parris and Alex Greenwood were all part of this season's title-winning squad.
"We have decided to show an example by investing even more [in the women's team] than in previous years," said Aulas.
"We are in the process of assembling the best team we have ever had with serious investments; investments that give an example that women's football shouldn't be secondary to men's football.