Bath chairman Bruce Craig has suggested it may not be possible to rearrange his club's European Champions Cup fixture with Toulon.
The two sides were scheduled to meet on Sunday at Stade Felix Mayol on Sunday, but that Pool Five fixture - together with the other French-based European matches this weekend - was postponed following Friday's terror attacks in Paris that killed 129 people and left scores critically injured.
In a statement announcing the decision on Saturday, European Professional Club Rugby (EPCR) chairman Simon Halliday said: "We are working to reschedule the five postponed matches in what is already a crowded rugby calendar, and we hope to be in a position to announce the new dates next week."
However, Craig told the Telegraph: "It is very clear to me that the Toulon match can't happen.
"The midweek option is not an option to my mind as that would be to the detriment of player welfare as well as the integrity of two competitions, an important Champions Cup game being squeezed in with all the attendant travel issues between two Premiership weekends.
"There is no way we should be letting that happen. You can't play three high-profile games in a week.
"In the wider context of what has happened in Paris, this is not a serious matter, of course it isn't. And I do understand why the decision was taken [to postpone the match].
"But from a rugby point of view, and from the point of view of the competition, this is an issue of significant consequence. There is no place to fit it in."
Toulon chairman Mourad Boudjellal has reportedly suggested the match could take place during next year's Six Nations, although the prospect of international sides releasing players for club duty appears unlikely.
Speaking to BBC Bristol on Monday, Halliday acknowledged the challenge facing EPCR.
"There is no immediate, obvious weekend we can choose. That is fact," he said.
"All the fixtures are already compressed, we have a unique problem."