Toulouse, who have started the defence of their French title with two away losses, will seek a first win of the season at home to another Top 14 heavyweight Racing 92, on Sunday.
Elsewhere, the third round of games opens with Christophe Urios, who led Castres to a title in 2018, returning to his former club as coach of Bordeaux-Begles.
As the French club season opens under the shadow of the Rugby World Cup, Toulouse are paying the price of success.
They are shorn of 10 players who are on international duty ahead of the competition, although back-row forward Francois Cros, released when France announced their final 31-squad on Monday, is back with the club.
On Friday, Toulouse announced Cros and two youngsters, prop Cyril Baille and scrum half Antoine Dupont, had signed contract extensions. Baille and Dupont will make Toulouse stronger in the future, but not just yet. They are off to Japan with France.
In the first two rounds, Toulouse lost away to the early-season pacesetters, 30-25 in Bordeaux and then 22-12 in Lyon.
Backs coach Clement Poitrenaud said on the club's website the team had been close in the first two games but had been punished for their "moments of weakness."
"The majority of players we have know our system for the most part," he said. "The problem is the number of players we have available. We are more stretched. We have less choice."
Poitrenaud said he was not worried about the two away losses.
"The season is long," he said. "We need to win at home, to give ourselves breathing room and confidence."
- Urios returns to Castres -
The Urios era has started well at Bordeaux-Begles: two matches, two wins and a bonus point leave them level with table-topping Lyon on nine points.
Now comes a different challenge for Urios.
His new team open the Top 14 weekend away to Castres, the club he left in the summer.
Urios has a long association with Castres. He played for the club, as a hooker, from 1990 to 1999, winning a French title in 1993. He coached them in two stints from 2002 and 2005 and from 2015 to 2019, leading them to a Top 14 title in 2018.
The relationship soured this spring as Castres struggled.
Yet Urios has a more pressing problem. Away form cost Bordeaux-Begles their playoff hopes last season. After two home victories, can they win away for the first time in 2019. Their last victory on the road was last December, when they won 32-13, at Castres's Stade Pierre-Fabre.
French Top 14 fixtures (all times GMT)
Castres v Bordeaux-Begles (1330), Toulon v Lyon (1530), Montpellier v La Rochelle, Stade Francais v Bayonne, Pau v Agen (all 1845)
Brive v Clermont (1450), Toulouse v Racing 92 (1900)