World Rugby chief executive Alan Gilpin said on Wednesday the coronavirus pandemic had cost the sport an estimated £1 billion (around R20 billion) in lost revenue.
International and professional club rugby union, as well as the amateur game, were all suspended last year due to Covid-19, with reigning world champions South Africa having yet to play a match since beating England in the 2019 World Cup final in Japan.
"We think from the work we've done over the last six to nine months through our member national unions that probably the overall damage is in the region of £1 billion," Gilpin told a conference call.
"We say that because we've worked, obviously, at the elite level of the game to understand the impacts of Covid and huge revenue drop-off have had.
"We don't know, of course, what the damage really is in the community game, and I don't think probably anyone does at this stage.
"What we have seen in countries that are starting to open up in the community is that players young and old are flooding back to rugby clubs in almost record numbers.
"We really need and hope that happens around the world and people get back to the sport quickly, then I think we can all move forward and be successful.
"I don't think we have got any predictions on how long it will take."
Gilpin was speaking as World Rugby, the 15-a-side code's global governing body outlined a four-year strategic plan until 2025 that includes confronting what he said were "the three Cs of Covid, calendar and concussion".
"The pandemic has forced us to abort community rugby across the globe, it's led to unprecedented disruption for the elite game and has created huge financial strain on our national member unions, on professional clubs and leagues across the world," said Gilpin.
"As an organisation, a sport and a family, this plan will guide how we tackle the three Cs of Covid, calendar and concussion, and build the foundations for a safer, stronger and more sustainable game for all."
Gilpin said World Rugby would hold talks with player groups such as Progressive Rugby, who are calling for reform of the sport.
Concussion remains a major concern for the game, with 2003 England World Cup-winner Steve Thompson among a group of former players suffering early-onset dementia symptoms who are taking legal action against rugby governing bodies.
"Over the last year, we have heard the brave stories and testimonies of former players who have come forward and talked about their struggles with dementia," said Gilpin.
"We are very proud of those players who have shared those experiences. They are part of the rugby family, and we will always stand with them.
"We will speak to the groups like Progressive Rugby. We have already spoken with several of their members, and we will continue to have an ongoing dialogue with them.
"We all share that same vision to create a safer, more sustainable game which future generations can enjoy," added Gilpin as he highlighted World Rugby programmes into concussion research, injury prevention and player well-being.