Former Ireland coach Eddie O'Sullivan says the cancellation of the men's Six Nations would be a "hammer blow" to the sport financially.
On Wednesday, it was confirmed that the Women's and the U20 Six Nations were being postponed until a later date, with the women's competition likely to be re-scheduled for a window in late spring/early summer ahead of the World Cup in the autumn.
However, despite the French government voicing some misgivings, the men's Six Nations remains on-track to proceed as originally planned, with the competition kicking off on the weekend of 6/7 February.
The French authorities recently barred their clubs from taking part in European competition due to concerns over the new Covid-19 variant, forcing the suspension of the competition.
The French government are seeking safety guarantees ahead of the Six Nations, particularly centring on their away games against Ireland and England. Sports Minister Roxana Maracineanu has thus far only approved the opening fixture against Italy in Rome.
"If the Six Nations would come unstuck now, it would be the kiss of death in terms of finances," O'Sullivan said on RTÉ Radio 1's Saturday Sport.
"I can't imagine the game will stop but it would be catastrophic. It would be hard to get over it.
"The French are genuinely concerned about travelling to Britain. They've three away games this year - in Italy, they've got to go to England and they've to come to Dublin. You can understand the concern in France. And it's not just about rugby, it's a national concern."
O'Sullivan ultimately does believe the Six Nations can be played off in February or March - provided nothing adverse occurs concerning the virus prior to or during that time.
"I think the Six Nations can be played off, I think there's a way through this, but that's if nothing bad happens. Let's say if there's an outbreak in one team, that could unhinge the whole championship. We're really on tenterhooks here.
"If everything goes to plan - and I understand the French government are looking for assurances - the Six Nations will go ahead. But if something goes wrong, if there's an outbreak of Covid (in a team) or a new strain comes in... We don't know. It's up in the air.
"Fingers crossed, the Six Nations will happen. Because if it doesn't it's another hammer blow to the game financially. Everyone's holding their breath at the moment because the cancellation of the Six Nations would do the most damage.
"At the moment, we're holding our breath on it. I think it's possible if things hold. If nothing untoward happens with the virus, I think it's possible for professional players to maintain the right protocols and get through the tournament. There's no one going to be in the stadiums, we can watch on television and it would save the tournament. But if anything goes wrong, the whole thing could derail in the middle of the tournament."
Meanwhile, the suspension of the Champions Cup is almost certain to force another change to the competition format.
Though no formal announcement has been made yet, Premiership Rugby CEO Darren Childs has gone on the record to say that the final two group games will not occur and, with a limited number of playing windows remaining, the competitions will jump straight to the knockout phase.
It is envisioned that the home and away quarter-final arrangement will be ditched and a 16-team knockout will be run off - although other alternatives have been mooted.
While acknowledging the necessity of the changes in the circumstances, O'Sullivan says the 2020-21 competition will have to have an asterisk placed alongside it.
"We'd like to say it doesn't but I think it does. Teams have played right through the competition based on the structure of it. In some cases, teams might have changed selections or they may have viewed games differently and then suddenly, the dynamics or the parameters of the tournament changed.
"So, as they say in America, you'd probably put an asterisk beside this year's tournament because you've changed the format of the tournament in mid-stream. So, whatever we say, it does affect it, there's no doubt about that.
"But I think rugby, like most other businesses, is in scramble mode at the moment. They're trying to find ways to get competitions finished in ways that seem reasonable.
"And you've even the starting up of new competitions. The Pro14 now morphs into the rainbow tournament. Trying to get the current Pro14 done and into the next one..."
While the pandemic has had a hugely detrimental affect on rugby's finances, O'Sullivan does point out that things might have been worse.
"Obviously, the unions are scrambling for money everywhere. The Australian rugby union are proposing a mini-World Cup now that would be integrated with the Rugby Championship.
"We're in this massive state of flux and it's all about keeping our head above water until we can get out the other side of this. It is what it is and there's no point in worrying about only to keep the game intact.
"Can you imagine the catastrophe this would be if it was a Rugby World Cup year?
"We've dodged a bullet that we got out of the Rugby World Cup done and we're in mid-cycle.
"The cancellation of the Rugby World Cup - or the postponement of it even, as we had in the Olympics - would be just beyond catastrophic for world rugby."