The resumption of the Top 14 immediately after Christmas has been disrupted by coronavirus as the league on Friday cancelled two games, including the one involving leaders Bordeaux Begles.
The French league said on Friday night that it called off Racing 92's home game with Pau and Bordeaux-Begles' visit to Toulon, both scheduled for Monday, "due to the health situation of the Racing 92, Pau and Bordeaux-Begles squads, following new tests carried out today".
Both Bordeaux-Begles and Racing 92 had announced earlier in the week that they were dealing with outbreaks and had cancelled training.
The Toulon-Bordeaux-Begles match was due to close the round on Monday evening. The league had already taken the precaution of pushing back the encounter between fifth-placed La Rochelle and Lyon, who are fourth to ensure it had a prime-time game.
The postponements follow a chaotic second round of European competition last week in which only two French clubs, Castres and Lyon, played their scheduled games.
The cancellations give Toulouse a chance to regain first place.
The defending champions lost at Bordeaux-Begles in their last match to cede first place, but are just two points behind their conquerers.
They entertain Stade Francais on Sunday, and both clubs are trying to fit a family Christmas into their plans.
Stade Francais have adjusted their travel plans for their visit to Toulouse to accommodate Santa.
The Parisians are allowing their squad to have a family Christmas and will fly down to southwest France on the morning of the game.
"We'll have a very short night's sleep," said coach Gonzalo Quesada. "We take the plane very early in the morning."
He lamented "preparations that are necessarily a little strange with Christmas."
Playing at home may allow Toulouse players a more relaxed Christmas.
"We'll take the 24th and 25th off and get together on the morning of the 26th for the match," Toulouse fullback Thomas Ramos said in an interview posted on the club website.
- 'Far more fans' -
Toulouse and Stade are the two clubs with the most French titles and like to call their encounters the Top14 'Classico'.
For the first time in two years, the hosts have opted to move a home Top14 game from their Ernest Wallon ground to the 33,000 Stadium de Toulouse, home of the local football club.
"These are big matches we like to play with far more fans and a bigger atmosphere," said Ramos. "We look forward to a full stadium."
Toulouse unwrapped some Christmas presents a day early when they announced on Friday that their co-captains, world player of the year Antoine Dupont and fellow French international Julien Marchand, had extended their contracts.
Montpellier, who have won five straight to climb to third in the table face last place Biarritz on Monday afternoon and could profit when the two teams immediately below them, Lyon and La Rochelle face off in the evening.
La Rochelle will be playing their first match since back row forward Kevin Gourdon announced on Tuesday that he was retiring at 31 because of a heart problem.
The last of his 221 appearances for the club was in their home game against Pau at the end of November.
Fixtures (all times GMT)
Perpignan v Castres (1500), Brive v Clermont (1700), Toulouse v Stade Francais (2005)
Biarritz v Montpellier (1800), La Rochelle v Lyon (2005)
Racing 92 v Pau, Toulon v Bordeaux Begles