Toulouse president Didier Lacroix said on Wednesday it was a difficult decision to move this month's European Champions Cup quarter-final with Ulster to Stade Ernest Wallon.
The last eight tie on September 20 was originally scheduled for the French town's Le Stadium which holds 33,000 but has been moved to the four-time European champions home ground, which will have a maximum capacity of 5,000 due to coronavirus guidelines.
Lacroix had hoped to gain a local dispensation to increase the crowd number for the fixture which had already sold 27,000 tickets.
"It's with a heavy heart that we have made this choice. The local council is in a red zone and it can't grant us an exemption," Lacroix said.
"A quarter-final (at a full Le Stadium) is 750,000 euros ($885,410) net for the club, now we'll split the profit which was in our financial budget by eight," he added.
Locks Joe Tekori and Richie Arnold will be available for the visit of the Irish province after they were banned for just one week for seperate incidents in last weekend's loss to Clermont.
Earlier in the day, French rugby federation president Bernard Laporte told newspaper l'Equipe he wanted to bypass the French league by discussing directly with the clubs who will be impacted by an enlargened Test window this autumn.
Les Bleus are set to play six games, in a reorganised schedule due to the Covid-19 pandemic, between October 24-December 5 which will clash with half a dozen rounds of the Top 14.
The record 20-time league champions are set to lose the likes of half-back partnership Antoine Dupont and Romain Ntamack for the period but Lacroix said domestic sides should negotiate collectively.
"Bernard is known for being outspoken, even if it's true that the subject concerns four or five clubs more than the rest, it concerns every French club, so it's obvious that the French league is around the table," Lacroix said.
"If we want the players to perform, they can't play all the games so we it has to be part of the discussion.
"What are the priority matches? France v Ireland, yes, because we can win the Six Nations and it's important for French rugby," he added.